3-pyridylcarbonyl-piperazinylsulfonyl derivatives

ABSTRACT

The present invention relates to novel piperazine derivatives; to processes for their preparation; to pharmaceutical compositions containing the derivatives; and to the use of the derivatives in therapy to treat diseases for which blocking the Ca v 2.2 calcium channels is beneficial.

This application is a continuation of U.S. Ser. No. 12/503,125 filedJul. 15, 2009 now U.S. Pat. No. 8,288,388 which claims priority to GBApplication No. 0813142.7 filed on Jul. 17, 2008 in the United Kingdom,the disclosures of which are incorporated by reference in theirentirety.

The present invention relates to novel piperazine derivatives; toprocesses for their preparation; to pharmaceutical compositionscontaining the derivatives; and to the use of the derivatives in therapyto treat diseases for which blocking the Ca_(v)2.2 calcium channels isbeneficial.

Pre-synaptic Ca_(v)2.2 (N-type) voltage-gated calcium channels in thedorsal horn of the spinal cord modulate the release of keypro-nociceptive neurotransmitters such as glutamate, substance P(SP) andcalcitonin-gene-related peptide (CGRP), indicating the potentialtherapeutic use of Ca_(v)2.2 calcium channel blockers as analgesics.

Peptidic ω-conotoxins, isolated from the venom of cone snails, have beenshown to be selective for Ca_(v)2.2 calcium channels and can block SPrelease in the spinal cord (Smith et al. (2002) Pain, 96: 119-127).Moreover, they have been shown to be antinociceptive in animal models ofchronic pain following intrathecal administration (Bowersox et al.(1996) Journal of Pharmacology and Experimental Therapeutics, 279:1243-1249; Smith et al. (2002) supra), and have been shown to beeffective analgesics in clinical use, particularly in the treatment ofneuropathic pain (Brose et al. (1997) Clinical Journal of Pain, 13:256-259).

In addition, Ca_(v)2.2 calcium channels have been shown to be importantfor normal neuronal function (Winquist et al. (2005) BiochemicalPharmacology, 70: 489-499). Therefore, the aim is to identify novelmolecules that preferentially block Ca_(v)2.2 under conditions ofincreased neuronal excitability, so-called use-dependent blockers, as isthe case in chronic pain syndromes.

WO 2007/111921 (Amgen Inc) describes a series of diazaheterocyclic amidederivatives which are claimed to be useful in the treatment of diabetes,obesity and related conditions and disorders. DE 10155684 (Bayer AG)describes a series of 2-[[(aminosulfonyl)phenyl]ureido]thiazoles asantibiotics. WO 2008/024284 (Merck & Co) describes a series ofsulfonylated piperazines as cannabinoid-1 (CB1) receptor modulatorswhich are claimed to be useful in the treatment for example ofpsychosis, cognitive disorders and Alzheimer's disease.

The present invention provides compounds which are capable of blockingthese Ca_(v)2.2 calcium channels.

In a first aspect there is provided a compound of formula (I), or apharmaceutically acceptable salt thereof, for use in therapy, wherein:

-   m and n are independently selected from 0, 1 and 2;-   where present, each R¹ is independently selected from C₁₋₄ alkyl,    C₁₋₄ alkoxy, C₃₋₆ cycloalkyl, cyano, NR^(1a)R^(1b) and halogen;-   R^(1a) and R^(1b) are independently selected from hydrogen, C₁₋₄    alkyl, C₃₋₆ cycloalkyl and a 4 to 6 membered heterocyclyl; or R^(1a)    and R^(1b) together with the nitrogen atom to which they are    attached form a 4 to 6 membered heterocyclic ring;-   where present, each R² is C₁₋₄ alkyl;-   R³ is hydrogen, halogen, cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy;-   R⁴ is hydrogen or C₁₋₄ alkyl;-   R⁵ is hydrogen, halogen, cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy;-   R⁶ is hydrogen, halogen, cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy;    such that at least 1 of R³, R⁴, R⁵ and R⁶ is a group other than    hydrogen.

In a second aspect there is provided a compound of formula (I), or asalt thereof, wherein

-   m and n are independently selected from 0, 1 and 2;-   where present, each R¹ is independently selected from C₁₋₄ alkyl,    C₁₋₄ alkoxy, C₃₋₆ cycloalkyl, cyano, NR^(1a)R^(1b) and halogen;-   R^(1a) and R^(1b) are independently selected from hydrogen, C₁₋₄    alkyl, C₃₋₆ cycloalkyl and a 4 to 6 membered heterocyclyl; or R^(1a)    and R^(1b) together with the nitrogen atom to which they are    attached form a 4 to 6 membered heterocyclic ring;-   where present, each R² is CO₁₄ alkyl;-   R³ is hydrogen, halogen, cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy;-   R⁴ is hydrogen or C₁₋₄ alkyl;-   R⁵ is hydrogen, halogen, cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy;-   R⁶ is hydrogen, halogen, cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy;-   such that at least 1 of R³, R⁴, R⁵ and R⁶ is a group other than    hydrogen;-   with the proviso that the compound is not-   1-[(4-chlorophenyl)sulfonyl]-4-[(6-methyl-3-pyridinyl)carbonyl]piperazine;-   1-[(5-bromo-3-pyridinyl)carbonyl]-4-[(4-chlorophenyl)sulfonyl]piperazine;-   1-[(3-chlorophenyl)sulfonyl]-4-(3-pyridinylcarbonyl)piperazine;-   1-[(5,6-dichloro-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;-   1-[(6-chloro-3-pyridinyl)carbonyl]-4-{[4-chloro-3-(trifluorom    ethyl)phenyl]sulfonyl}piperazine;-   1-[(5,6-dichloro-3-pyridinyl)carbonyl]-4-({4-[(trifluorom    ethyl)oxy]phenyl}sulfonyl)piperazine;-   1-[(5-bromo-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;-   1-[(6-chloro-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;-   1-{[4-chloro-3-(trifluoromethyl)phenyl]sulfonyl}-4-(3-pyridinylcarbonyl)piperazine;-   1-(3-pyridinylcarbonyl)-4-{[3-(trifluoromethyl)phenyl]sulfonyl}piperazine;-   1-(3-pyridinylcarbonyl)-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;-   1-(3-pyridinylcarbonyl)-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine;-   1-{[4-chloro-3-(trifluoromethyl)phenyl]sulfonyl}-4-[(6-methyl-3-pyridinyl)carbonyl]piperazine;-   1-[(6-methyl-3-pyridinyl)carbonyl]-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine;-   1-{[6-(methyloxy)-3-pyridinyl]carbonyl}-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine;-   4-({4-[(6-methyl-3-pyridinyl)carbonyl]-1-piperazinyl}sulfonyl)benzonitrile;-   1-{[4-chloro-3-(trifluoromethyl)phenyl]sulfonyl}-4-{[2-(ethyloxy)-3-pyridinyl]carbonyl}piperazine;-   1-{[2-(ethyloxy)-3-pyridinyl]carbonyl}-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;-   1-{[2-(ethyloxy)-3-pyridinyl]carbonyl}-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine;-   1-[(3-chlorophenyl)sulfonyl]-4-{[2-(1-pyrrolidinyl)-3-pyridinyl]carbonyl}piperazine;-   4-[(4-{[2-(1-pyrrolidinyl)-3-pyridinyl]carbonyl}-1-piperazinyl)sulfonyl]benzonitrile;-   1-{[2-(ethyloxy)-3-pyridinyl]carbonyl}-4-[(3-fluorophenyl)sulfonyl]piperazine;-   1-{[2-(ethyloxy)-3-pyridinyl]carbonyl}-4-[(3-fluorophenyl)sulfonyl]piperazine;-   1-[(3-chlorophenyl)sulfonyl]-4-{[2-(1-pyrrolidinyl)-3-pyridinyl]carbonyl}piperazine;-   1-[(5,6-dichloro-3-pyridinyl)carbonyl]-4-[(4-fluorophenyl)sulfonyl]piperazine;-   1-[(4-fluorophenyl)sulfonyl]-4-{[2-(1-pyrrolidinyl)-3-pyridinyl]carbonyl}piperazine;-   1-[(3-fluorophenyl)sulfonyl]-4-{[2-(1-pyrrolidinyl)-3-pyridinyl]carbonyl}piperazine;    and-   1-[(5-bromo-3-pyridinyl)carbonyl]-4-[(4-chlorophenyl)sulfonyl]piperazine.

It is understood that in formula (I), when present, R¹ may be attachedto any one of the four possible carbon atoms in the pyridyl ring.

As used herein, the term “alkyl” (when used as a group or as part of agroup) refers to a straight or branched hydrocarbon chain containing thespecified number of carbon atoms. For example, C₁₋₆alkyl means astraight or branched hydrocarbon chain containing at least 1 and at most6 carbon atoms. Examples of alkyl include, but are not limited to;methyl (Me), ethyl (Et), n-propyl, i-propyl, t-butyl, n-hexyl andi-hexyl.

As used herein, the term “alkoxy” (when used as a group or as part of agroup) refers to an —O-alkyl group wherein alkyl is as definedhereinbefore.

The term ‘halogen’ is used herein to describe, unless otherwise stated,a group selected from fluoro (fluorine), chloro (chlorine), bromo(bromine) or iodo (iodine). In one embodiment, the term ‘halogen’ isused herein to describe, unless otherwise stated, a group selected fromchloro (chlorine) or bromo (bromine).

The term C₁₋₄ haloalkyl as used herein refers to a C₁₋₄ alkyl group asdefined herein substituted with one or more halogen groups, e.g. CF₃,CF₂H or CF₃CH₂.

The term C₁₋₄ haloalkoxy as used herein refers to an C₁₋₄ alkoxy groupas defined herein substituted with one or more halogen groups, e.g.—O—CF₃.

The term C₃₋₆ cycloalkyl as used herein refers to a saturated monocyclichydrocarbon ring of 3 to 6 carbon atoms. Examples of such groups includecyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

The term 4 to 6 membered heterocyclic ring and its monovalent radicalrefers to a 4 to 6 membered saturated monocyclic ring which contains 1or 2 heteroatoms independently selected from oxygen, nitrogen andsulphur. Suitable examples of such groups include pyrrolidinyl,piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl and azetidinyl.

In one embodiment of the first or second aspect, R¹ is selected fromC₁₋₄ alkyl, C₁₋₄ alkoxy, cyano and NR^(1a)R^(1b). In another embodimentof the first or second aspect, R¹ is selected from C₁₋₄ alkyl and C₁₋₄alkoxy. In one particular embodiment of the first or second aspect, R¹is selected from methyl and methoxy. In a more particular embodiment ofthe first or second aspect, R¹ is selected from 2-methyl, 6-methyl,2-methoxy and 6-methoxy. In an even more particular embodiment of thefirst or second aspect, R¹ is 2-methyl.

In one embodiment of the first or second aspect, R¹ is NR^(1a)R^(1b) andR^(1a) and R^(1b) are independently selected from hydrogen and C₁₋₄alkyl, or R^(1a) and R^(1b) together with the nitrogen atom to whichthey are attached form a 4 to 6 membered heterocyclic ring. In anotherembodiment of the first or second aspect, R^(1a) and R^(1b) are C₁₋₄alkyl, or R^(1a) and R^(1b) together with the nitrogen atom to whichthey are attached form a 4 or 5 membered heterocyclic ring. In oneparticular embodiment of the first or second aspect, R^(1a) and R^(1b)are C₁₋₄ alkyl, or R^(1a) and R^(1b) together with the nitrogen atom towhich they are attached form a morpholinyl, pyrrolidinyl or azetidinylring. In a more particular embodiment of the first or second aspect,R^(1a) and R^(1b) are C₁₋₄ alkyl. In an even more particular embodimentof the first or second aspect, R^(1a) and R^(1b) are selected frommethyl and ethyl. In an even more particular embodiment, R^(1a) andR^(1b) together with the nitrogen atom to which they are attached form amorpholinyl, pyrrolidinyl or azetidinyl ring.

In one embodiment of the first or second aspect, n is 0 or 1. In anotherembodiment of the first or second aspect, n is 1. In a furtherembodiment of the first or second aspect, n is 0.

In one embodiment of the first or second aspect, R² is methyl. Inanother embodiment of the first or second aspect, R² is methyl and mis 1. In a particular embodiment of the first or second aspect, thecompound of formula (I) is a compound of formula (Ia)

In a more particular embodiment of the first or second aspect, thecompound of formula (I) is a compound of formula (Ib)

In one embodiment of the first or second aspect, R³ is C₁₋₄ haloalkyl orC₁₋₄ haloalkoxy. In one particular embodiment of the first or secondaspect, R³ is trifluoromethyl, trifluoromethoxy or difluoromethoxy. In amore particular embodiment of the first or second aspect, R³ istrifluoromethyl.

In one embodiment of the first or second aspect, R⁴ is hydrogen ormethyl. In one particular embodiment of the first or second aspect, R⁴is hydrogen.

In one embodiment of the first or second aspect, R⁵ and R⁶ areindependently selected from hydrogen and C₁₋₄ haloalkyl. In oneparticular embodiment of the first or second aspect, R⁵ and R⁶ areindependently selected from hydrogen and trifluoromethyl. In a moreparticular embodiment of the first or second aspect, R⁵ and R⁶ arehydrogen.

In one embodiment of the first or second aspect, R¹ is C₁₋₄ alkyl, C₁₋₄alkoxy, cyano or NR^(1a)R^(1b), particularly R¹ is C₁₋₄ alkyl or C₁₋₄alkoxy, more particularly R¹ is methyl or methoxy, even moreparticularly R¹ is selected from 2-methyl, 6-methyl, 2-methoxy and6-methoxy, yet even more particularly R¹ is 2-methyl; n is 0 or 1,particularly n is 1; R² is methyl, particularly R² is methyl and m is 1,more particularly 2-methyl relative to the piperazine carbonyl bond (asin formula (Ia)), even more particularly (2S)-2-methyl (as in formula(Ib)); R³ is C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy, particularly R³ istrifluoromethyl, trifluoromethoxy or difluoromethoxy, more particularlyR³ is trifluoromethyl; R⁴ is hydrogen or methyl, particularly R⁴ ishydrogen; R⁵ and R⁶ are independently selected from hydrogen and C₁₋₄haloalkyl, particularly R⁵ and R⁶ are independently selected fromhydrogen and trifluoromethyl, more particularly R⁵ and R⁶ are hydrogen.

In one embodiment of the first or second aspect, R¹ is C₁₋₄ alkyl, C₁₋₄alkoxy, cyano or NR^(1a)R^(1b); n is 0 or 1; when present, R² is methyl;R³ is C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy;

R⁴ is hydrogen or methyl; R⁵ and R⁶ are independently selected fromhydrogen and C₁₋₄ haloalkyl.

In one embodiment of the first or second aspect, R¹ is C₁₋₄ alkyl orC₁₋₄ alkoxy; n is 1; R² is methyl and m is 1; R³ is trifluoromethyl,trifluoromethoxy or difluoromethoxy; R⁴ is hydrogen; R⁵ and R⁶ areindependently selected from hydrogen and trifluoromethyl.

In one embodiment of the first or second aspect, R¹ is methyl ormethoxy; n is 1; R² is 2-methyl relative to the piperazine carbonyl bond(as in formula (Ia)) and m is 1; R³ is trifluoromethyl, trifluoromethoxyor difluoromethoxy; R⁴ is hydrogen; R⁵ and R⁶ are hydrogen.

In one embodiment of the first or second aspect, R¹ is selected from2-methyl, 6-methyl, 2-methoxy and 6-methoxy; n is 1; R² is (2S)-2-methyl(as in formula (Ib)) and m is 1; R³ is trifluoromethyl, trifluoromethoxyor difluoromethoxy; R⁴ is hydrogen; R⁵ and R⁶ are hydrogen.

In one embodiment of the first or second aspect, R¹ is NR^(1a)R^(1b) andR^(1a) and R^(1b) are independently hydrogen or C₁₋₄ alkyl, or R^(1a)and R^(1b) together with the nitrogen atom to which they are attachedform a 4 to 6 membered heterocyclic ring, particularly R^(1a) and R^(1b)are independently C₁₋₄ alkyl, or R^(1a) and R^(1b) together with thenitrogen atom to which they are attached form a 4 or 5 memberedheterocyclic ring, more particularly R^(1a) and R^(1b) are C₁₋₄ alkyl,or R^(1a) and R^(1b) together with the nitrogen atom to which they areattached form a morphonlinyl, pyrrolidine or azetidinyl ring, even moreparticularly R^(1a) and R^(1b) are C₁₋₄ alkyl, yet even moreparticularly R^(1a) and R^(1b) are selected from methyl and ethyl; n is0 or 1, particularly n is 1; R² is methyl, particularly R² is methyl andm is 1, more particularly 2-methyl relative to the piperazine carbonylbond (as in formula (Ia)), even more particularly (2S)-2-methyl (as informula (Ib)); R³ is C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy, particularly R³is trifluoromethyl, trifluoromethoxy or difluoromethoxy, moreparticularly R³ is trifluoromethyl; R⁴ is hydrogen or methyl,particularly R⁴ is hydrogen; R⁵ and R⁶ are independently selected fromhydrogen and C₁₋₄ haloalkyl, particularly R⁵ and R⁶ are independentlyselected from hydrogen and trifluoromethyl, more particularly R⁵ and R⁶are hydrogen.

In one embodiment of the first or second aspect, R¹ is NR^(1a)R^(1b) andR^(1a) and R^(1b) are independently hydrogen or C₁₋₄ alkyl, or R^(1a)and R^(1b) together with the nitrogen atom to which they are attachedform a 4 to 6 membered heterocyclic ring; n is 0 or 1; when present, R²is methyl; R³ is C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy; R⁴ is hydrogen ormethyl; R⁵ and R⁶ are independently selected from hydrogen and C₁₋₄haloalkyl.

In one embodiment of the first or second aspect, R^(1a) and R^(1b) areindependently C₁₋₄ alkyl, or R^(1a) and R^(1b) together with thenitrogen atom to which they are attached form a 4 or 5 memberedheterocyclic ring; n is 1; R² is methyl and m is 1; R³ istrifluoromethyl, trifluoromethoxy or difluoromethoxy; R⁴ is hydrogen ormethyl; R⁵ and R⁶ are independently selected from hydrogen andtrifluoromethyl.

In one embodiment of the first or second aspect, R^(1a) and R^(1b) areC₁₋₄ alkyl, or R^(1a) and R^(1b) together with the nitrogen atom towhich they are attached form a morphonlinyl, pyrrolidine or azetidinylring, n is 1; R² is 2-methyl relative to the piperazine carbonyl bond;R³ is trifluoromethyl, trifluoromethoxy or difluoromethoxy; R⁴ ishydrogen; R⁵ and R⁶ are independently selected from hydrogen.

In one embodiment of the first or second aspect, the compound isselected from a compound of Examples 1 to 76, or a salt thereof.

In a third aspect, the compound is a compound of formula (Ic), or apharmaceutically acceptable salt thereof, for use in therapy, wherein

-   R¹ represents C₁₋₄ alkyl, C₁₋₄ alkoxy, cyano or morpholinyl;-   m and n independently represent an integer from 0 to 1;-   R² represents C₁₋₄ alkyl;-   R³ represents halogen, cyano, trifluoromethyl, trifluoromethoxy or    difluoromethoxy;-   R⁴ represents hydrogen or methyl;-   such that when R³ represents cyano, R⁴ represents a group other than    hydrogen.

In a fourth aspect, the compound is a compound of formula (Ic), or asalt thereof, wherein

-   R¹ represents C₁₋₄ alkyl, C₁₋₄ alkoxy, cyano or morpholinyl;-   m and n independently represent an integer from 0 to 1;-   R² represents C₁₋₄ alkyl;-   R³ represents halogen, cyano, trifluoromethyl, trifluoromethoxy or    difluoromethoxy;-   R⁴ represents hydrogen or methyl;-   such that when R³ represents cyano, R⁴ represents a group other than    hydrogen;-   with the proviso that the compound is not-   1-[(4-chlorophenyl)sulfonyl]-4-[(6-methyl-3-pyridinyl)carbonyl]piperazine;-   1-(3-pyridinylcarbonyl)-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;-   1-(3-pyridinylcarbonyl)-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine;-   1-[(6-methyl-3-pyridinyl)carbonyl]-4-({4-[(trifluorom    ethyl)oxy]phenyl}sulfonyl)piperazine;-   1-{[6-(methyloxy)-3-pyridinyl]carbonyl}-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine;-   4-({4-[(6-methyl-3-pyridinyl)carbonyl]-1-piperazinyl}sulfonyl)benzonitrile;-   1-{[2-(ethyloxy)-3-pyridinyl]carbonyl}-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;    and-   1-{[2-(ethyloxy)-3-pyridinyl]carbonyl}-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine.

In one embodiment of the third or fourth aspect, n represents 0 or 1. Ina further embodiment of the third or fourth aspect, n represents 1. Whenpresent, in one embodiment of the third or fourth aspect, R¹ representsC₁₋₄ alkyl, C₁₋₄ alkoxy or cyano. In a further embodiment of the thirdor fourth aspect, R¹ represents C₁₋₄ alkyl. In a yet further embodimentof the third or fourth aspect, R¹ represents methyl, particularly2-methyl or 6-methyl, even more particularly 2-methyl.

In one embodiment of the third or fourth aspect, m represents 0 or 1. Ina further embodiment of the third or fourth aspect, m represents 1.

When present, in one embodiment of the third or fourth aspect, R²represents C₁₋₃ alkyl. In a further embodiment of the third or fourthaspect, R² represents methyl or ethyl. In a yet further embodiment ofthe third or fourth aspect, R² represents methyl.

In one embodiment of the third or fourth aspect, R³ represents chlorine,cyano, trifluoromethyl, trifluoromethoxy or difluoromethoxy. In afurther embodiment of the third or fourth aspect, R³ representstrifluoromethyl.

In another embodiment of the first to fourth aspect, the compound is(2S)-2-Methyl-1-[(6-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine;or(2S)-2-Methyl-1-[(2-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine,or a salt thereof. More particularly the compound is(2S)-2-Methyl-1-[(2-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine,or a salt thereof.

Certain compounds as defined in the first to fourth aspect may in somecircumstances form acid addition salts thereof. It will be appreciatedthat for use in medicine compounds of formula (I) may be used as salts,in which case the salts should be pharmaceutically acceptable.Pharmaceutically acceptable salts include those described by Berge,Bighley and Monkhouse, J. Pharm. Sci., 1977, 66, 1-19. The term“pharmaceutically acceptable salts” includes salts prepared frompharmaceutically acceptable acids, including inorganic and organicacids. Such acids include acetic, benzenesulfonic, benzoic,camphorsulfonic, citric, ethanesulfonic, fumaric, gluconic, glutamic,hydrobromic, hydrochloric, isethionic, lactic, maleic, malic, mandelic,methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric,succinic, sulfuric, tartaric, p-toluenesulfonic acid, and the like.

Examples of pharmaceutically acceptable salts include those formed frommaleic, fumaric, benzoic, ascorbic, pamoic, succinic, hydrochloric,sulfuric, bismethylenesalicylic, methanesulfonic, ethanedisulfonic,propionic, tartaric, salicylic, citric, gluconic, aspartic, stearic,palmitic, itaconic, glycolic, p-aminobenzoic, glutamic, benzenesulfonic,cyclohexylsulfamic, phosphoric and nitric acids.

It will be appreciated by those skilled in the art that certainprotected derivatives of the compounds as defined in the first to fourthaspect, which may be made prior to a final deprotection stage, may notpossess pharmacological activity as such, but may, in certain instances,be administered orally or parenterally and thereafter metabolised in thebody to form compounds as defined in the first to fourth aspect whichare pharmacologically active. Such derivatives may therefore bedescribed as “prodrugs”. All protected derivatives and prodrugs ofcompounds defined in the first to fourth aspect are included within thescope of the invention. Examples of suitable pro-drugs for the compoundsof the present invention are described in Drugs of Today, Volume 19,Number 9, 1983, pp 499-538 and in Topics in Chemistry, Chapter 31, pp306-316 and in “Design of Prodrugs” by H. Bundgaard, Elsevier, 1985,Chapter 1 (the disclosures in which documents are incorporated herein byreference). It will further be appreciated by those skilled in the art,that certain moieties, known to those skilled in the art as“pro-moieties”, for example as described by H. Bundgaard in “Design ofProdrugs” (the disclosure in which document is incorporated herein byreference) may be placed on appropriate functionalities when suchfunctionalities are present within the compounds as defined in the firstand second aspects. Therefore, in a further aspect, the inventionprovides a prodrug of a compound as defined in the first to fourthaspect.

It will be appreciated that certain compounds as defined in the first tofourth aspect, or their salts, may exist as solvates, such as hydrates.Where solvates exist, this invention includes within its scopestoichiometric and non-stoichiometric solvates.

It will be appreciated that certain compounds as defined in the first tofourth aspect, or their salts, may exist in more than one polymorphicform. The invention extends to all such forms whether in a purepolymorphic form or when admixed with any other material, such asanother polymorphic form.

Certain compounds as defined in the first to fourth aspect are capableof existing in stereoisomeric forms (e.g. diastereomers and enantiomers)and the invention extends to each of these stereoisomeric forms and tomixtures thereof including racemates. The different stereoisomeric formsmay be separated one from the other by the usual methods, or any givenisomer may be obtained by stereospecific or asymmetric synthesis. Theinvention also extends to any tautomeric forms and mixtures thereof.

The subject invention also includes isotopically-labelled compounds,which are identical to the compounds as defined in the first to fourthaspect, but for the fact that one or more atoms are replaced by an atomhaving an atomic mass or mass number different from the atomic mass ormass number most commonly found in nature. Examples of isotopes that canbe incorporated into compounds of the invention include isotopes ofhydrogen, carbon, nitrogen, fluorine, such as ³H, ¹¹C, ¹⁴C and ¹⁸F.

Compounds as defined in the first to fourth aspect and salts of saidcompounds that contain the aforementioned isotopes and/or other isotopesof other atoms are within the scope of the present invention.Isotopically-labelled compounds of the present invention, for examplethose into which radioactive isotopes such as ³H, ¹⁴C are incorporated,are useful in drug and/or substrate tissue distribution assays.Tritiated, i.e., ³H, and carbon-14, i.e., ¹⁴C, isotopes are particularlypreferred for their ease of preparation and detectability. ¹¹C and ¹⁸Fisotopes are particularly useful in PET (positron emission tomography).PET is useful in brain imaging. Further, substitution with heavierisotopes such as deuterium, i.e., ²H, can afford certain therapeuticadvantages resulting from greater metabolic stability, for exampleincreased in vivo half-life or reduced dosage requirements and, hence,may be preferred in some circumstances. Isotopically labelled compoundsof formula (I) and following of this invention can generally be preparedby carrying out the procedures disclosed in the Schemes and/or in theExamples below, by substituting a readily available isotopicallylabelled reagent for a non-isotopically labelled reagent. In oneembodiment, compounds as defined in the first to fourth aspect or saltsthereof are not isotopically labelled.

Throughout the specification, general formulae are designated by Romannumerals (I), (II), (III), (IV), etc. Subsets of these general formulaeare defined as (Ia), (Ib), (Ic), etc. (IVa), (IVb), (IVc), etc.

Compounds as defined in the first to fourth aspect may be prepared asset forth in the following Schemes and in the examples. The followingprocesses form another aspect of the present invention.

The present invention also provides a process for the preparation of acompound as defined in the first to fourth aspect, or a salt thereof,which process comprises:

-   (a) reacting a compound of formula (II)

or a derivative thereof, with a compound of formula (III)

wherein R¹, R², R³, R⁴, R⁵, R⁶, m and n are as defined above and L¹represents a suitable leaving group such as a halogen atom (e.g.chlorine or bromine) or a hydroxyl group activated by commerciallyavailable amide coupling reagents (for example, HOBT, HBTU or HATU);

-   (b) reacting a compound of formula (IV)

with a compound of formula (V)

wherein R¹, R², R³, R⁴, R⁵, R⁶, m and n are as defined above and L²represents a suitable leaving group such as a halogen atom (e.g.chlorine or bromine);

-   (c) interconversion to other compounds as defined in the first to    fourth aspect.

Process (a) typically comprises reaction of a compound of formula (II)with a compound of formula (III) in a suitable solvent such asacetonitrile, tetrahydrofuran, N,N-dimethylformamide or dichloromethane,in the presence of a suitable base, (for example, triethylamine,di-isopropylethylamine or DIPEA) at 00° C. to ambient temperature (forexample, room temperature).

Process (b) typically comprises reaction of a compound of formula (IV)and (V) in the presence of a suitable solvent (such as dichloromethaneor acetonitrile) in the presence of a suitable base, (for exampletriethylamine, di-isopropylethylamine or DIPEA) at 0° C. to ambienttemperature (for example, room temperature). Alternatively, process (b)may typically comprise reaction of the intermediates in the presence ofa suitable base as a solvent (for example pyridine).

Process (c) may be performed using conventional interconversionprocedures such as epimerisation, oxidation, reduction, alkylation,nucleophilic or electrophilic aromatic substitution. One such example ofinterconversion may be interconversion of a compound as defined in thefirst to fourth aspect wherein R³ represents bromine to a compound asdefined in the first to fourth aspect wherein R³ represents cyano. Suchinterconversion may be carried out by treating the bromine compound witha cyanide salt (for example copper (I) cyanide) in a suitable solvent(such as N,N-dimethylformamide) at elevated temperatures (such as 200°C. using microwave irradiation). Alternatively the interconversion maybe carried out using a cyanide salt (for example zinc cyanide) in thepresence of a source of a palladium catalyst (for exampletris(dibenzylideneacetone)dipalladium(0) and ligand (for example 1,1′-bis(diphenylphosphino)ferrocene) in a suitable solvent (such asN,N-dimethylformamide) at elevated temperatures (such as 120° C.).

This kind of interconversion may also be carried out on intermediates ofcompounds as defined in the first to fourth aspect, for example oncompounds of formula (VII).

Another example of interconversion is from a compound of formula (VII)where R⁴ represents bromine to a compound where R⁴ represents methyl.Such interconversion may be carried out by treating the bromine compoundwith a methylboronic acid or ester (eg trimethylboroxin) in the presenceof a palladium catalyst (for example tetrakistriphenylphosphinepalladium (0)) in a suitable solvent (such as 1,4-dioxane) at elevatedtemperatures (such as 100° C.).

A different example of an interconversion to other compounds as definedin the first to fourth aspect is shown in the Scheme below:

wherein R¹, R², R³, R⁴, R⁵, R⁶ and m are as defined above, n is 0 or 1,and Q is C₁₋₄ alkyl or C₃₋₆ cycloalkyl.

Step (i) typically comprises reacting a compound of formula (Id) with aC₁₋₄ alkylzinc halide in the presence of a catalyst such as PdCl₂ (dppf)in a suitable solvent such as 1,4-dioxane at an elevated temperature(such as 100° C.). Alternatively, step (i) may comprise reacting acompound of formula (Id) with a suitable C₁₋₄ alkylboronic acid or C₃₋₆cycloalkylboronic acid in the presence of a catalyst such aspalladium(II)acetate, ligand such as tricyclohexylphosphine and basesuch as potassium phosphate in a solvent such as a mixture of tolueneand water at an elevated temperature.

A further example of an interconversion to other compounds as defined inthe first to fourth aspect is shown in the Scheme below:

wherein R¹, R^(1a), R^(1b), R², R³, R⁴, R⁵, R⁶ and m are as definedabove, and n is 0 or 1.

Step (i) typically comprises reacting a compound of formula (If) with anamine HNR^(1a)R^(1b) in a suitable solvent such as isopropanol in themicrowave in the temperature range 100-180° C. for the time required toachieve good conversion to (Ie), such as, for example, 1 h to 48 h.

Compounds of formula (II) may be prepared in accordance with thefollowing Scheme:

wherein R², R³, R⁴, R⁵, R⁶, m and L² are as defined above and P¹represents a suitable protecting group such as t-butoxycarbonyl.Alternatively, if P¹ is H then step (ii) is not required.

Step (i) typically comprises reacting a compound of formula (V) and (VI)in a suitable solvent, such as DCM or MeCN in the presence of a base,(for example triethylamine, di-isopropylethylamine or DIPEA) at 0° C. toambient temperature (for example ambient temperature). Alternatively,step (i) may typically be carried out using a suitable base as asolvent, for example pyridine, or step (i) may also be carried out in asolvent mixture of THF and water, using a suitable base such as sodiumhydroxide.

Step (ii) typically comprises a deprotection reaction. For example, whenP¹ represents t-butoxycarbonyl, step (ii) will typically comprisetreatment with an acid, for example hydrochloric acid or trifluoroaceticacid, in a solvent (such as 1,4-dioxane, dichloromethane or a mixture ofmethanol and 1,4-dioxane).

Compounds of formula (IV) may be prepared in accordance with thefollowing Scheme:

wherein R², m, R¹, n and P¹ are as defined above.

Step (i) typically comprises reacting a compound of formula (VI) with acompound of formula (III) in a suitable solvent (such as MeCN, THF, DMFor DCM) in the presence of a suitable base (for example, triethylamine,di-isopropylethylamine or DIPEA) at 0° C. to ambient temperature (forexample ambient temperature).

Step (ii) typically comprises a deprotection reaction which may becarried out in an analogous manner to Step (ii) above.

Compounds of formula (III), (V) and (VI) are either commerciallyavailable, or may be prepared by known methods.

Compounds which can block the Ca_(v)2.2 calcium channels may be usefulin the treatment or prophylaxis of pain, including acute pain, chronicpain, chronic articular pain, musculoskeletal pain, neuropathic pain,inflammatory pain, visceral pain, pain associated with cancer, painassociated with migraine, tension headache and cluster headaches, painassociated with functional bowel disorders, lower back and neck pain,pain associated with sprains and strains, sympathetically maintainedpain; myositis, pain associated with influenza or other viral infectionssuch as the common cold, pain associated with rheumatic fever, painassociated with myocardial ischemia, post operative pain, cancerchemotherapy, headache, toothache and dysmenorrhea.

‘Chronic articular pain’ conditions include rheumatoid arthritis,osteoarthritis, rheumatoid spondylitis, gouty arthritis and juvenilearthritis.

‘Pain associated with functional bowel disorders’ includes non-ulcerdyspepsia, non-cardiac chest pain and irritable bowel syndrome.

‘Neuropathic pain’ syndromes include: diabetic neuropathy, sciatica,non-specific lower back pain, trigeminal neuralgia, multiple sclerosispain, fibromyalgia, HIV-related neuropathy, post-herpetic neuralgia,trigeminal neuralgia, and pain resulting from physical trauma,amputation, phantom limb syndrome, spinal surgery, cancer, toxins orchronic inflammatory conditions. In addition, neuropathic painconditions include pain associated with normally non-painful sensationssuch as “pins and needles” (paraesthesias and dysesthesias), increasedsensitivity to touch (hyperesthesia), painful sensation followinginnocuous stimulation (dynamic, static, thermal or cold allodynia),increased sensitivity to noxious stimuli (thermal, cold, mechanicalhyperalgesia), continuing pain sensation after removal of thestimulation (hyperpathia) or an absence of or deficit in selectivesensory pathways (hypoalgesia).

Other conditions which could potentially be treated by compounds asdefined in the first to fourth aspect include neurodegenerative diseasesand neurodegeneration, neurodegeneration following trauma, tinnitus,dependence on a dependence-inducing agent such as opioids (e.g.morphine), CNS depressants (e.g. ethanol), psychostimulants (e.g.cocaine) and nicotine.

Neurodegenerative diseases include dementia, particularly degenerativedementia (including senile dementia, dementia with Lewy bodies,Alzheimer's disease, Pick's disease, Huntingdon's chorea, Parkinson'sdisease and Creutzfeldt-Jakob disease, ALS, motor neuron disease);vascular dementia (including multi-infarct dementia); as well asdementia associated with intracranial space occupying lesions; trauma;infections and related conditions (including HIV infection, meningitisand shingles); metabolism; toxins; anoxia and vitamin deficiency; andmild cognitive impairment associated with ageing, particularly AgeAssociated Memory Impairment.

Compounds as defined in the first to fourth aspect may also be usefulfor neuroprotection and in the treatment or prophylaxis ofneurodegeneration following trauma such as stroke, cardiac arrest,pulmonary bypass, traumatic brain injury, spinal cord injury or thelike.

Another condition which could potentially be treated by compounds asdefined in the first to fourth aspect is spasticity or muscularhypertonicity.

Thus, in an embodiment of the first and third aspect, the therapy is tothe treatment or prophylaxis of any of the disorders described herein,in particular pain. In one particular embodiment, the therapy is to thetreatment of any of the disorders described herein, in particular pain.

According to a further aspect, there is provided a use of a compound asdefined in the first to fourth aspect, or a pharmaceutically acceptablesalt thereof, in the manufacture of a medicament for the treatment orprophylaxis of any of the disorders herein, in particular pain. Moreparticularly, there is provided a use of a compound as defined in thefirst to fourth aspect, or a pharmaceutically acceptable salt thereof,in the manufacture of a medicament for the treatment of any of thedisorders herein.

According to another aspect, there is provided a method of treatment orprophylaxis of any of the disorders herein, in particular pain inhumans, which method comprises the administration to the human in needof such treatment or prophylaxis, an effective amount of a compound asdefined in the first to fourth aspect, or a pharmaceutically acceptablesalt thereof.

In the context of the present invention, the term “treatment” refers tosymptomatic treatment and the term “prophylaxis” is used to meanpreventing symptoms in an already afflicted subject or preventingrecurrence of symptoms in an afflicted subject and is not limited tocomplete prevention of an affliction.

In order to use a compound as defined in the first to fourth aspect or apharmaceutically acceptable salt thereof for the treatment orprophylaxis of humans and other mammals it is normally formulated inaccordance with standard pharmaceutical practice as a pharmaceuticalcomposition. Therefore in another aspect of the invention there isprovided a pharmaceutical composition comprising a compound as definedin the first to fourth aspect, or a pharmaceutically acceptable saltthereof, adapted for use in human or veterinary medicine.

In order to use compounds as defined in the first to fourth aspect intherapy, they will normally be formulated into a pharmaceuticalcomposition in accordance with standard pharmaceutical practice. Thepresent invention also provides a pharmaceutical composition, whichcomprises a compound as defined in the first to fourth aspect, or apharmaceutically acceptable salt thereof, and optionally apharmaceutically acceptable excipient.

When used in the treatment or prophylaxis of pain, the compound asdefined in the first to fourth aspect or a pharmaceutically acceptablesalt thereof may be used in combination with other medicaments indicatedto be useful in the treatment or prophylaxis of pain of neuropathicorigin including neuralgias, neuritis and back pain, and inflammatorypain including osteoarthritis, rheumatoid arthritis, acute inflammatorypain, back pain and migraine. Such therapeutic agents include forCompound COX-2 (cyclooxygenase-2) inhibitors, such as celecoxib,deracoxib, rofecoxib, valdecoxib, parecoxib, COX-189 or2-(4-ethoxy-phenyl)-3-(4-methanesulfonyl-phenyl)-pyrazolo[1,5-b]pyridazine(WO99/012930); 5-lipoxygenase inhibitors; NSAIDs (non-steroidalanti-inflammatory drugs) such as diclofenac, indomethacin, nabumetone oribuprofen; bisphosphonates, leukotriene receptor antagonists; DMARDs(disease modifying anti-rheumatic drugs) such as methotrexate; adenosineA1 receptor agonists; sodium channel blockers, such as lamotrigine; NMDA(N-methyl-D-aspartate) receptor modulators, such as glycine receptorantagonists or memantine; ligands for the α₂δ-subunit of voltage gatedcalcium channels, such as gabapentin, pregabalin and solzira; tricyclicantidepressants such as amitriptyline; neurone stabilising antiepilepticdrugs; cholinesterase inhibitors such as galantamine; mono-aminergicuptake inhibitors such as venlafaxine; opioid analgesics; localanaesthetics; 5HT₁ agonists, such as triptans, for Compound sumatriptan,naratriptan, zolmitriptan, eletriptan, frovatriptan, almotriptan orrizatriptan; nicotinic acetyl choline (nACh) receptor modulators;glutamate receptor modulators, for Compound modulators of the NR2Bsubtype; EP₄ receptor ligands; EP₂ receptor ligands; EP₃ receptorligands; EP₄ agonists and EP₂ agonists; EP₄ antagonists; EP₂ antagonistsand EP₃ antagonists; cannabinoid receptor ligands; bradykinin receptorligands; vanilloid receptor or Transient Receptor Potential (TRP)ligands; and purinergic receptor ligands, including antagonists at P2X₃,P2X_(2/3), P2X₄, P2X₇ or P2X_(4/7); KCNQ/Kv7 channel openers, such asretigabine; Additional COX-2 inhibitors are disclosed in U.S. Pat. Nos.5,474,995, 5,633,272; 5,466,823, 6,310,099 and 6,291,523; and in WO96/25405, WO 97/38986, WO 98/03484, WO 97/14691, WO99/12930, WO00/26216,WO00/52008, WO00/38311, WO01/58881 and WO002/18374.

When used in the treatment or prophylaxis of Alzheimer's disease, thecompound as defined in the first to fourth aspect or a pharmaceuticallyacceptable salt thereof may be used in combination with othermedicaments indicated to be useful as either disease modifying orsymptomatic treatments of Alzheimer's disease.

Suitable examples of such other therapeutic agents may be agents knownto modify cholinergic transmission such as 5-HT_(1A) antagonists, (e.g.lecozotan), 5-HT6 antagonists, M1 muscarinic agonists, M2 muscarinicantagonist, acetylcholinesterase inhibitors (e.gtetrahydroaminoacridine, donepezil or rivastigmine), or allostericmodulators, nicotinic receptor agonists or allosteric modulators,symptomatic agents such as 5-HT6 receptor antagonists, e.g. SB742457, H3receptor antagonists e.g. GSK189254 and GSK239512, 5-HT4 receptoragonist, PPAR agonists, also NMDA receptor antagonists or modulators,also disease modifying agents such as β or γ-secretase inhibitors (e.g.R-flurbiprofen), also AMPA positive modulators and Glycine TransporterReuptake inhibitors.

When a compound as defined in the first to fourth aspect or apharmaceutically acceptable salt thereof is used in combination withanother therapeutic agent, the compounds may be administered eithersequentially or simultaneously by any convenient route.

The invention thus provides, in a further aspect, a combinationcomprising a compound as defined in the first to fourth aspect or apharmaceutically acceptable salt thereof together with a furthertherapeutic agent or agents.

A pharmaceutical composition of the invention, which may be prepared byadmixture, suitably at ambient temperature and atmospheric pressure, isusually adapted for oral, parenteral or rectal administration and, assuch, may be in the form of tablets, capsules, oral liquid preparations,powders, granules, lozenges, reconstitutable powders, injectable orinfusable solutions or suspensions or suppositories. Orallyadministrable compositions are generally preferred.

Tablets and capsules for oral administration may be in unit dose form,and may contain conventional excipients, such as binding agents,fillers, tabletting lubricants, disintegrants and acceptable wettingagents. The tablets may be coated according to methods well known innormal pharmaceutical practice.

Oral liquid preparations may be in the form of, for example, aqueous oroily suspension, solutions, emulsions, syrups or elixirs, or may be inthe form of a dry product for reconstitution with water or othersuitable vehicle before use. Such liquid preparations may containconventional additives such as suspending agents, emulsifying agents,non-aqueous vehicles (which may include edible oils), preservatives,and, if desired, conventional flavourings or colourants.

For parenteral administration, fluid unit dosage forms are preparedutilising a compound of the invention or pharmaceutically acceptablesalt thereof and a sterile vehicle. The compound, depending on thevehicle and concentration used, can be either suspended or dissolved inthe vehicle. In preparing solutions, the compound can be dissolved forinjection and filter sterilised before filling into a suitable vial orampoule and sealing. Advantageously, adjuvants such as a localanaesthetic, preservatives and buffering agents are dissolved in thevehicle. To enhance the stability, the composition can be frozen afterfilling into the vial and the water removed under vacuum. Parenteralsuspensions are prepared in substantially the same manner, except thatthe compound is suspended in the vehicle instead of being dissolved, andsterilization cannot be accomplished by filtration. The compound can besterilised by exposure to ethylene oxide before suspension in a sterilevehicle. Advantageously, a surfactant or wetting agent is included inthe composition to facilitate uniform distribution of the compound.

The composition may contain from 0.1% to 99% by weight, preferably from10% to 60% by weight, of the active material, depending on the method ofadministration. The dose of the compound as defined in the first tofourth aspect or a pharmaceutically acceptable salt thereof used in thetreatment or prophylaxis of the aforementioned disorders will vary inthe usual way with the seriousness of the disorders, the weight of thesufferer, and other similar factors. However, as a general guidesuitable unit doses may be 0.05 to 1000 mg, more suitably 1.0 to 200 mg,and such unit doses may be administered more than once a day, forexample two or three a day. Such therapy may extend for a number ofweeks, months, years or even life.

A further aspect to the invention is a pharmaceutical compositioncomprising 0.05 to 1000 mg of a compound as defined in the first tofourth aspect or a pharmaceutically acceptable salt thereof, and 0 to 3g more suitably 0 to 2 g of at least one pharmaceutically acceptablecarrier.

All publications, including but not limited to patents and patentapplications, cited in this specification are herein incorporated byreference as if each individual publication were specifically andindividually indicated to be incorporated by reference herein as thoughfully set forth.

Abbreviations:

-   Ar: argon-   aq.: aqueous-   dba: dibenzylideneacetone-   DCM: dichloromethane-   DIPEA: N,N-diisopropylethylamine-   DMF: N,N-dimethylformamide-   DMSO: dimethylsulfoxide-   DPPF: 1,1′-bis(diphenylphosphino)ferrocene-   EDC: 1-ethyl-3-(3-dimethyllaminopropyl)carbodiimide hydrochloride-   EtOAc: ethyl acetate-   HATU: O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium    hexafluorophosphate-   HBTU:    O-benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate-   HOBT: hydroxybenzotriazole-   iHex: isohexane-   LCMS: Liquid Chromatography Mass Spectrometry-   MS: mass spectrometry-   MeCN: acetonitrile-   MDAP: mass directed automated preparative liquid chromatography.-   MeOH: methanol-   rt: room temperature-   sat.: saturated-   SCX: strong cation exchange chromatography-   SPE: solid phase extraction-   SP4: Biotage-SP4® automated purification system-   THF: tetrahydrofuran-   TFA: trifluoroacetic acid-   Pd₂ (dba)₃: tris(dibenzylideneacetone)dipalladium(0)-   Pd(PPh₃)₄: tetrakis(triphenylphosphine)palladium-   h: hour(s)-   min: minute(s)-   Boc: t-butoxycarbonyl-   PdCl₂ (dppf)₃:    (1,1′-bis(diphenylphosphino)ferrocene)dichloropalladium(II)-   API-ES: atmospheric pressure ionization electro-spray

EXAMPLES

The preparation of a number of supporting compounds as defined in thefirst to fourth aspect are described below.

In the procedures that follow, after each starting material, referenceto an intermediate is typically provided. This is provided merely forassistance to the skilled chemist. The starting material may notnecessarily have been prepared from the batch referred to.

Description 1 1-{[4-(Trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of 1,1-dimethylethyl 1-piperazinecarboxylate (5.00 g, 26.8mmol) in DCM (200 ml) was added DIPEA (9.85 ml, 56.4 mmol) and then4-(trifluoromethyl)benzenesulfonyl chloride (7.22 g, 29.5 mmol). Thereaction mixture was stirred for 1.5 hours at room temperature. Thereaction mixture was then reduced to dryness in vacuo, to yield thetitle compound.

m/z (API-ES) 295 [M+H−100]⁺

To a solution of 1,1-dimethylethyl4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate in1,4-dioxane (100 ml) was added 4M HCl in 1,4-dioxane (50 ml, 200 mmol)and 3 drops of distilled water. The reaction mixture was stirredovernight. Reaction mixture was then reduced to dryness in vacuo.

The residue was dissolved in DCM (200 ml) and washed with 2M NaOH (50ml), twice. The organic layer was dried over magnesium sulphate, theinsolubles removed by filtration, and filtrate reduced to dryness invacuo to yield the title compound (6.60 g) as a pale yellow solid.

m/z (API-ES) 295 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 5 ppm 2.89-2.98 (m, 4 H), 2.99-3.09 (m, 4H), 3.71 (s, 1 H), 7.77-7.85 (m, 2 H), 7.85-7.92 (m, 2 H).

Description 2(3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of 1,1-dimethylethyl (2S)-2-methyl-1-piperazinecarboxylate(5.00 g, 25.0 mmol, supplier Small Molecules Inc.) in DCM (200 ml) wasadded DIPEA (11.4 ml, 65.5 mmol) and 4-(trifluoromethyl)benzenesulfonylchloride (5.68 g, 23.2 mmol). The reaction mixture was stirred for 1hour. DCM (200 ml) was added to the reaction mixture which wastransferred to a separating funnel. The solution was washed withsaturated sodium bicarbonate solution (50 ml, twice) and then withdistilled water (50 ml). The organic layer was dried over magnesiumsulphate which was removed by filtration and the filtrate was evaporatedto dryness on the rotary evaporator to give 8.90 g of white solid. Thesolid was dissolved in 1,4-dioxane (30 ml) and 4M HCl in 1,4-dioxane (10ml) and a few drops of water were added and the reaction mixture wasstirred for 1 hour. Then further 4M HCl in 1,4-dioxane (20 ml) was addedand the reaction stirred overnight. The reaction mixture was evaporatedto dryness in vacuo and the residue was dissolved in MeOH and loadedonto an SCX column (Biotage). The column was washed with MeOH (2 columnvolumes) and the product was eluted with 1M ammonia in MeOH. LCMS showeda large amount of desired product present in the MeOH wash, so this wasevaporated to dryness on the rotary evaporator. The residue wasdissolved in EtOAc (100 ml) and extracted with 2M aq. HCl (50 ml). Theaqueous layer was basified with 2M aqueous NaOH solution until pHremained above 7 and extracted with EtOAc (100 ml). The organic layerwas evaporated to dryness on the rotary evaporator to yield the titlecompound as a white solid (4.34 g).

m/z (API-ES) 309 [M+H]⁺

¹H NMR (400 MHz, MeOH-d4) δ ppm 1.36 (d, J=6.6 Hz, 3 H), 2.62-2.73 (m, 1H), 2.85-2.97 (m, 1 H), 3.19-3.29 (m, 1 H), 3.45-3.54 (m, 2 H),3.80-3.95 (m, 2 H), 7.95 (d, J=8.3 Hz, 2 H), 8.05 (d, J=8.3 Hz, 2 H).

Alternative Synthesis of(3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine:Description 2a

(2S)-2-methylpiperazine (15 g, 150 mmol) was dissolved intetrahydrofuran (300 mL) and the solution was cooled down to 0° C.Sodium hydroxide (150 mL, 449 mmol) was added, then4-(trifluoromethyl)benzenesulfonyl chloride (40 g, 164 mmol) (dissolvedin 200 ml THF) was added dropwise and the resulting mixture was stirredfor 1 h. Further 4-(trifluoromethyl)benzenesulfonyl chloride (0.06 eq,2.2 g) was added and mixture stirred for 10 min. The mixture was dilutedwith DCM (500 ml) and water (500 ml) and stirred for min. The phaseswere separated, the aqueous layer was extracted with DCM (1000 ml) andthe organic phases concentrated under reduced pressure. The residue wastaken-up with 1 M HCl (500 ml) and washed with DCM in order to extractedimpurities. The aqueous phase was basified to pH=9 with NaOH 3M,extracted with DCM (3×500 ml) and the combined organic phases dried overNa₂SO₄ before the solvent was removed under reduced pressure to give thetitle compound (30 g).

m/z (API-ES) 309 [M+H]⁺

¹H NMR (400 MHz, CDCl₃) δ ppm 1.06 (d, J=7.2 Hz, 3H), 1.94 (t, J=10.4Hz, 1H), (td, J=11.2, 4.0 Hz, 1H), 2.88-3.07 (m, 3H), 3.66 (m, 2H), 7.83(d, J=8.4 Hz, 2H), 7.90 (d, J=8.4 Hz, 2H).

Description 3 1,1-Dimethylethyl(3S)-4-[(4-chlorophenyl)sulfonyl]-3-methyl-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (3S)-3-methyl-1-piperazinecarboxylate(10.0 g, 49.9 mmol, supplier Aldrich) in pyridine (30 ml) was added4-chlorobenzenesulfonyl chloride (12.7 g, 59.9 mmol) portionwise. Thereaction was stirred at room temperature under an argon atmosphere for 2hours. The reaction was then evaporated, partitioned between 2N aq. HCl(70 ml) and DCM (80 ml). The aqueous was further extracted with DCM(2×80 ml) and the combined DCM layers were passed through a hydrophobicfrit and evaporated. The product was dried under vacuum at 40° C. for 18hours to yield the title compound as an orange solid (24.14 g).

¹H-NMR (400 MHz, CHLOROFORM-d) δ 1.03 (3H, dd, J=6.8, 0.4 Hz), 1.43 (9H,s), 3.05 (1H, m), 3.10 (1H, m), 3.15 (1H, m), 3.60 (1H, m), 3.80 (1H,m), 4.10 (2H, m), 7.48 (2H, m), 7.74 (2H, m).

Description 4 (2S)-1-[(4-Chlorophenyl)sulfonyl]-2-methylpiperazinehydrochloride

1,1-Dimethylethyl(3S)-4-[(4-chlorophenyl)sulfonyl]-3-methyl-1-piperazinecarboxylate (maybe prepared as described in Description 3) (crude weight 24.14 g,theoretical 49.9 mmol) was suspended in 4M HCl in 1,4-dioxane (80 mL,excess) and stirred vigorously for 3 hours. The sample was evaporated,suspended in diethyl ether (100 mL) and filtered through a sinter. Thecollected solid was dried under vacuum at 40° C. for 18 hours to yieldthe title compound as a yellow solid (15.45 g).

m/z (API-ES) 275 [M+H]⁺

¹H NMR (MeOH-d4) δ 1.21 (3H, d, J=7.0 Hz), 2.91-3.45 (5H, br m), 3.89(1H, m), 4.38 (1H, m), 7.64 (2H, m), 7.88 (2H, m).

Description 5 1,1-Dimethylethyl(3R)-3-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (3R)-3-methyl-1-piperazinecarboxylate(1.5 g, 7.49 mmol, supplier Aldrich) in DCM (30 ml) was added DIPEA(1.962 ml, 11.23 mmol) and then portionwise addition of4-(trifluoromethyl)benzenesulfonyl chloride (2.2 g, 8.99 mmol) at roomtemperature. The resultant mixture was stirred under an atmosphere of Arfor 2 hours before addition of 1M HCl solution (75 ml) and DCM (75 ml).The layers were separated and the aqueous layer was then re-extractedwith DCM (75 ml), the organic layers were combined and washed withsaturated brine solution (100 ml). The organic layers were thenseparated, dried (MgSO₄) and concentrated to dryness giving the titlecompound (3.39 g).

m/z (API-ES) 309 [M+H−100]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 5 ppm 1.03 (d, J=6.7 Hz, 3 H), 1.43 (s, 9H), 2.65-3.22 (m, 3 H), 3.54-4.27 (m, 4 H), 7.78 (d, J=8.2 Hz, 2 H),7.93 (d, J=8.2 Hz, 2 H).

Description 6(2R)-2-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride

To a solution of 1,1-dimethylethyl(3R)-3-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate(may be prepared as described in Description 5) (3.39 g, 8.30 mmol) in1,4-dioxane (20 ml) was added HCl (4M in 1,4-dioxane) (10.37 ml, 41.5mmol) and the resultant mixture stirred under an atmosphere of Ar for 16hours. A further 5 ml of 4M HCl in dioxane was added and the mixturestirred at room temperature for 72 hours. The mixture was concentratedto dryness and the residue triturated with diethyl ether and the solidcollected by filtration giving the title compound (2.507 g) as a whitepowder.

m/z (API-ES) 309 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.16 (d, J=7.0 Hz, 3H), 2.72-2.86 (m, 1H), 2.96 (dd, J=13.0, 4.28 Hz, 1 H), 3.08-3.24 (m, 2 H), 3.26-3.34 (m,1H), 3.70-3.84 (m, 1H), 4.16-4.32 (m, 1H), 8.03 (d, J=8.4 Hz, 2 H), 8.09(d, J=8.3 Hz, 2 H), 9.16 (br. s. 2H).

Description 7 1,1-Dimethylethyl(3S)-3-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (3S)-3-methyl-1-piperazinecarboxylate(2.05 g, 10.24 mmol) in DCM (50 ml) was added DIPEA (2.68 ml, 15.35mmol) and the mixture stirred at room temperature for 10 minutes beforeaddition of 4-(trifluoromethyl)benzenesulfonyl chloride (3.00 g, 12.28mmol) at 0° C. The resultant mixture stirred under an atmosphere ofArgon for 16 hours before addition of water (50 ml) and DCM (30 ml). Thelayers were separated using a hydrophobic frit and the organic layersconcentrated to dryness giving the title compound (4.4 g) as a whitesolid.

m/z (API-ES) 309 [M+H−100]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.03 (d, J=6.7 Hz, 3 H) 1.43 (s, 9H) 2.59-3.33 (m, 3 H) 3.43-4.35 (m, 4 H) 7.77 (d, J=8.3 Hz, 2 H) 7.93(d, J=8.3 Hz, 2 H).

Description 8(2S)-2-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride

To a solution of 1,1-dimethylethyl(3S)-3-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate(may be prepared as described in Description 7) (4.4 g, 10.77 mmol) in1,4-dioxane (30 ml) was added HCl (4M in 1,4-dioxane) (5.39 ml, 21.55mmol) and the mixture stirred at room temperature for 2 hours. A furtherportion of HCl (4M in 1,4-dioxane) (16.16 ml, 64.6 mmol) was then addedand the mixture stirred for a further 16 hours. The volatiles were thenremoved in vacuo giving the title compound (3.8 g) as a white solid.

m/z (API-ES) 309 [M+H]⁺

¹H NMR (400 MHz, MeOH-d4) 5 ppm 1.20 (d, J=7.1 Hz, 3 H) 2.95-3.25 (m, 3H) 3.36-3.45 (m, 1 H) 3.56-3.77 (m, 1 H) 3.87-4.00 (m, 1 H) 4.34-4.51(m, 1 H) 7.94 (d, J=8.3 Hz, 2 H) 8.08 (d, J=8.2 Hz, 2 H)

Description 9 1,1-Dimethylethyl(2S)-4-[(4-bromo-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (2S)-2-methyl-1-piperazinecarboxylate(2.00 g, 9.99 mmol) and DIPEA (2.62 ml, 14.98 mmol) in dry DCM (25 ml)at 0° C. under Ar was added 4-bromo-2-methylbenzenesulfonyl chloride(2.96 g, 10.98 mmol) and the resulting yellow solution allowed to warmto rt, then stirred at rt for 18 hours. Semi-saturated aq NH₄Cl (40 ml)was added, then the aq extracted with DCM (30 ml). The combined organiclayers were passed through a hydrophobic frit, then concentrated invacuo to give a yellow oil (5.01 g). Flash chromatography (silica; Flash40M; linear gradient (6-50%) EtOAc in isohexane) gave the title compoundas a pale yellow oil (3.52 g).

m/z (API-ES) 333 and 335, 1:1, [M+H−100]⁺ ¹H NMR (400 MHz, CHLOROFORM-d)5 ppm 1.19 (d, J=6.7 Hz, 3 H), 1.44 (s, 9 H), 2.59 (td, J=12.0, 3.4 Hz,1 H), 2.61 (s, 3 H), 2.78 (dd, J=12.0, 3.8 Hz, 1 H), 3.11 (td, J=12.0,3.2 Hz, 1 H), 3.44 (dt, J=12.0, 2.0 Hz, 1 H), 3.59-3.65 (m, 1 H), 3.93(d, J=12.0 Hz, 1 H), 4.33 (br. s., 1 H), 7.45-7.51 (m, 2 H), 7.72 (d,J=8.4 Hz, 1 H).

Description 10 1,1-Dimethylethyl (2S)-4-[(4-cyano-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate

Ar was bubbled through a solution of 1,1-dimethylethyl(2S)-4-[(4-bromo-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate (may be prepared asdescribed in Description 9) (3.51 g, 8.10 mmol) in dry DMF (40 ml) for0.5 hours, then Zn(CN)₂ (0.523 g, 4.45 mmol), Pd₂ (dba)₃ (0.223 g, 0.243mmol) and DPPF (0.269 g, 0.486 mmol) were added and the resulting brownsolution stirred at 120° C. under Ar for 2.5 hours. The mixture wascooled to room temperature, concentrated in vacuo and the residuepartitioned between DCM (100 ml) and water (100 ml). The aqueous layerwas extracted with DCM (2×100 ml), then the combined organic layerspassed through a hydrophobic frit. Concentration gave a brown residue(4.31 g). Flash chromatography (silica; linear gradient (6-50%) EtOAc inisohexane) gave the title compound as a yellow solid (2.88 g).

m/z (API-ES) 280 [M+H−100]⁺

¹H NMR (400 MHz, CHLOROFORM-d) ppm 1.20 (d, J=6.8 Hz, 3 H), 1.44 (s, 9H), 2.65 (td, J=12.0, 3.4 Hz, 1 H), 2.68 (s, 3 H), 2.86 (dd, J=12.0, 4.2Hz, 1 H), 3.13 (td, J=12.0, 2.8 Hz, 1 H), 3.49 (dt, J=12.0, 1.8 Hz, 1H), 3.63-3.69 (m, 1 H), 3.95 (d, J=12.0 Hz, 1 H), 4.35 (br. s., 1 H),7.61-7.65 (m, 2 H), 7.96 (d, J=6.8 Hz, 1 H).

Description 113-Methyl-4-{[(3S)-3-methyl-1-piperazinyl]sulfonyl}benzonitrile

A solution of 1,1-dimethylethyl(2S)-4-[(4-cyano-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate(may be prepared as described in Description 10) (2.88 g, 7.59 mmol) andTFA (10 ml, 130 mmol) in dry DCM (10 ml) was stirred at room temperaturefor 1 hour, then concentrated in vacuo, azeotroping with toluene (25 ml)to give a brown oil. This was partitioned between DCM (50 ml) andsaturated aqueous NaHCO₃ (50 ml), then the aqueous layer was extractedwith DCM (50 ml). The combined organic layers were passed through ahydrophobic frit and concentrated in vacuo to give the title compound asa yellow oil (2.29 g).

m/z (API-ES) 280 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.06 (d, J=6.4 Hz, 3 H), 2.33 (dd,J=11.6, 10.2 Hz, 1 H), 2.67 (s, 3 H), 2.69-2.75 (td, J=11.5, 3.1 Hz, 1H), 2.82-2.92 (m, 2 H), 3.03 (dt, J=12.1, 2.6 Hz, 1 H), 3.54-3.65 (m, 2H), 7.59-7.67 (m, 2 H), 7.99 (d, J=8.6 Hz, 1 H).

Description 12(3R)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of 1,1-dimethylethyl (2R)-2-methyl-1-piperazinecarboxylate(2.95 g, 14.73 mmol) in DCM (120 ml) was added DIPEA (5.40 ml, 30.9mmol) and then 4-(trifluoromethyl)benzenesulfonyl chloride (3.96 g,16.20 mmol). The reaction mixture was stirred 2.5 hours at roomtemperature then washed with water (250 ml), dried on a phase separationcartridge and concentrated in vacuo. The obtained product was dissolvedin 1,4-dioxane (60 ml) and treated with 4M aq. HCl in 1,4-dioxane (18.41ml, 73.6 mmol) overnight. The mixture was concentrated under vacuo thendissolved in EtOAc (150 ml), washed with 2N aq. NaOH solution (200 ml)then dried on a phase separation cartridge and concentrated in vacuo.The product was then dissolved in EtOAc (100 ml) and extracted with 2Maq. HCl (2×200 ml). 2M aq. NaOH solution was added to the aqueous layeruntil basic pH then the product was extracted with EtOAc (500 ml). Theorganic layer was dried on a phase separation cartridge and concentratedunder vacuo to give the title compound (3.76 g).

m/z (API-ES) 309 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 5 ppm 1.05 (d, J=6.4 Hz, 3 H) 1.93 (t,J=10.6 Hz, 1 H) 2.31 (td, J=11.2, 3.4 Hz, 1 H) 2.86-3.08 (m, 3 H)3.59-3.73 (m, 2 H) 7.82 (d, J=8.3 Hz, 2 H) 7.89 (d, J=8.2 Hz, 2 H).

Description 13(2S)-2-Methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine

To a solution of 1,1-dimethylethyl (3S)-3-methyl-1-piperazinecarboxylate(1 g, 4.99 mmol) in DMF (5 ml) was added 6-methyl-3-pyridinecarboxylicacid (0.685 g, 0.340 mmol), HOBT.H₂O (0.765 g, 4.99 mmol) and HBTU(1.894 g, 4.99 mmol). Finally DIPEA (2.62 ml, 14.98 mmol) was added andthe reaction mixture was stirred at room temperature for 20 hours.Solvent was removed by evaporation and EtOAc was added to the residueand the solution was extracted with saturated aqueous sodium bicarbonateand sodium chloride solutions. The organic layer was evaporated todryness and dissolved in dioxane (100 ml) and stirred with 4M HCl indioxane (15 ml) and water (0.25 ml) overnight. The solution wasevaporated to dryness and purified using an ion exchange column (SCX,Biotage) to give the title compound as an oil (1.04 g)

¹H NMR (400 MHz, CHLOROFORM-d) 5 ppm 1.36 (dd, J=6.8, 1.8 Hz, 3 H),2.02-3.35 (m, 7 H), 2.60 (s, 3 H), 7.22 (d, J=8.0 Hz, 1 H), 7.63 (d,J=8.0, 2.3 Hz, 1 H), 8.53 (d, J=1.8 Hz, 1 H).

Description 14 1-[(6-methyl-3-pyridinyl)carbonyl]piperazine

This compound was prepared in a similar manner as the compound ofDescription 13.

¹H NMR (400 MHz, CDCl₃) 5 ppm 2.60 (s, 3H), 2.8-3.1 (m, 4H), 3.4-3.6 (m,2H), 3.7-3.9 (m, 2H), 7.22 (d, J=8.0 Hz, 1H), 7.66 (dd, J=8.0, 2.4 Hz,1H), 8.55 (d, J=2.4 Hz, 1H).

Description 15 1,1-Dimethylethyl(3S)-4-[(4-bromo-2-methylphenyl)sulfonyl]-3-methyl-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (3S)-3-methyl-1-piperazinecarboxylate(2.00 g, 9.99 mmol) and DIPEA (2.62 ml, 15.0 mmol) in dry DCM (25 ml) at0° C. under Ar was added 4-bromo-2-methylbenzenesulfonyl chloride (2.96g, 11.0 mmol) and the resulting yellow solution allowed to warm to rt,then stirred at rt for 90 min. Semi-saturated NH₄Cl (25 ml) was added,then the aqueous extracted with DCM (20 ml). The combined organic layerswere passed through a hydrophobic frit, then concentrated under vacuumto give a pale yellow oil (4.99 g). Flash chromatography (silica; Flash40M; linear gradient (6-50%) EtOAc in isohexane) gave the title compoundas a viscous clear oil (4.46 g).

m/z (API-ES) 333 and 335 [M+H−100]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.18 (d, J=6.7 Hz, 3 H), 1.45 (s, 9H), 2.56 (s, 3 H), 2.69-2.91 (m, 1 H), 2.93-3.12 (m, 1 H), 3.20 (td,J=12.8 and 3.3 Hz, 1H), 3.37 (d, J=12.8 Hz, 1 H), 3.78-4.06 (m, 3 H),7.47 (s, 2 H), 7.83 (d, J=8.3 Hz, 1 H).

Description 16 1,1-dimethylethyl(3S)-4-[(4-cyano-2-methylphenyl)sulfonyl]-3-methyl-1-piperazinecarboxylate

Ar was bubbled through a solution of 1,1-dimethylethyl(3S)-4-[(4-bromo-2-methylphenyl)sulfonyl]-3-methyl-1-piperazinecarboxylate(may be prepared as described in Description 15) (4.32 g, 9.98 mmol) indry DMF (40 ml) for 30 min, then Zn(CN)₂ (0.645 g, 5.49 mmol), Pd₂(dba)₃ (0.274 g, 0.299 mmol) and DPPF (0.332 g, 0.599 mmol) were addedand the resulting brown solution stirred at 120° C. under Ar for 40 min.The mixture was cooled to room temperature, concentrated under vacuumand the residue partitioned between DCM (50 ml) and semi-saturated brine(50 ml). The aqueous layer was extracted with DCM (2×50 ml), then thecombined organic layers passed through a hydrophobic frit. Concentrationunder vacuum gave a brown residue (5.75 g). Flash chromatography(silica; Flash 40M; linear gradient (6-50%) EtOAc in isohexane) gave thetitle compound as a white solid (3.71 g).

m/z (API-ES) 280 [M+H−100]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.18 (d, J=6.7 Hz, 3 H), 1.44 (s, 9H), 2.62 (s, 3 H), 2.70-2.90 (m, 1 H), 2.94-3.14 (m, 1 H), 3.23 (td,J=12.8 and 3.2 Hz, 1 H), 3.41 (d, J=12.8 Hz, 1 H), 3.80-4.19 (m, 3 H),7.59-7.64 (m, 2 H), 8.07 (d, J=8.4 Hz, 1 H)

Description 173-methyl-4-{[(2S)-2-methyl-1-piperazinyl]sulfonyl}benzonitrile

A solution of 1,1-dimethylethyl(3S)-4-[(4-cyano-2-methylphenyl)sulfonyl]-3-methyl-1-piperazinecarboxylate(may be prepared as described in Description 16) (3.71 g, 9.78 mmol) andTFA (5.00 ml, 64.9 mmol) in dry DCM (15 ml) was stirred at rt for 1 h,then concentrated under vacuum, azeotroping with toluene (25 ml). Theresidue was dissolved in MeOH (20 ml) and added to an SCX-2 cartridge(50 g), washing with MeOH. The product was eluted with 2M NH₃ in MeOH;concentration under vacuum gave the title compound as a white solid(2.50 g).

m/z (API-ES) 280 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.30 (d, J=6.8 Hz, 3 H), 2.63 (s, 3H), 2.66 (td, J=11.9 and 3.9 Hz, 1 H), 2.79 (d, J=12.3 Hz, 1 H), 2.94(dd, J=12.3 and 3.5 Hz, 2 H), 3.24 (td, J=11.6 and 3.0 Hz, 1 H),3.27-3.33 (m, 1 H), 3.91-3.98 (m, 1 H), 7.58-7.62 (m, 2 H), 8.07 (d,J=8.6 Hz, 1 H)

Description 18 1,1-dimethylethyl(2R)-4-[(4-bromo-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (2R)-2-methyl-1-piperazinecarboxylate(2.00 g, 9.99 mmol) and DIPEA (2.62 ml, 15.0 mmol) in dry DCM (25 ml) at0° C. under Ar was added 4-bromo-2-methylbenzenesulfonyl chloride (2.96g, 11.0 mmol) and the resulting pale yellow solution stirred at 0° C.for 1 h. Semi-saturated NH₄Cl (20 ml) was added, then the aqueousextracted with DCM (30 ml). The combined organic layers were passedthrough a hydrophobic frit, then concentrated under vacuum to give ayellow oil (5.12 g). Flash chromatography (silica; Flash 40M; lineargradient (6-50%) EtOAc in isohexane) gave the title compound as a clearviscous oil (4.34 g).

m/z (API-ES) 333 and 335 [M+H−100]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.19 (d, J=6.7 Hz, 3 H), 1.44 (s, 9H), 2.59 (td, J=12.0, 3.2 Hz, 1 H), 2.61 (s, 3 H), 2.78 (dd, J=11.9, 3.8Hz, 1 H), 3.11 (td, J=12.9, 3.5 Hz, 1 H), 3.44 (dt, J=11.9, 1.9 Hz, 1H), 3.62 (ddt, J=11.8, 3.5, 1.8 Hz, 1 H), 3.93 (d, J=13.3 Hz, 1 H),4.29-4.37 (m, 1 H), 7.44-7.51 (m, 2 H), 7.72 (d, J=8.4 Hz, 1 H).

Description 19 1,1-dimethylethyl(2R)-4-[(4-cyano-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate

Ar was bubbled through a solution of 1,1-dimethylethyl(2R)-4-[(4-bromo-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate(may be prepared as described in Description 18) (4.34 g, 10.0 mmol) indry DMF (40 ml) for 30 min, then Zn(CN)₂ (0.647 g, 5.51 mmol), Pd₂(dba)₃ (0.275 g, 0.300 mmol) and DPPF (0.333 g, 0.601 mmol) were addedand the resulting brown solution stirred at 120° C. under Ar for 1 h.The mixture was cooled to room temperature, concentrated under vacuumand the residue partitioned between DCM (100 ml) and water (100 ml). Theaqueous layer was extracted with DCM (2×50 ml), then the combinedorganic layers passed through a hydrophobic frit. Concentration gave abrown residue that was purified by flash chromatography (silica; Flash40M; linear gradient (8-66%) EtOAc in isohexane) to give the titlecompound as a viscous pale yellow oil (3.42 g).

m/z (API-ES) 280 [M+H−100]⁺

¹H NMR (400 MHz, CHLOROFORM-d) ppm 1.19 (d, J=6.8 Hz, 3 H), 1.44 (s, 9H), 2.65 (td, J=12.1, 3.5 Hz, 1 H), 2.68 (s, 3 H), 2.85 (dd, J=12.1, 3.7Hz, 1 H), 3.12 (td, J=13.0, 3.5 Hz, 1 H), 3.48 (dt, J=12.0, 1.9 Hz, 1H), 3.66 (ddt, J=11.9, 3.5, 1.8 Hz, 1 H), 3.94 (d, J=13.4 Hz, 1 H),4.30-4.39 (m, 1 H), 7.61-7.65 (m, 2 H), 7.96 (d, J=8.6 Hz, 1 H).

Description 203-methyl-4-{[(3R)-3-methyl-1-piperazinyl]sulfonyl}benzonitrile

A solution of 1,1-dimethylethyl(2R)-4-[(4-cyano-2-methylphenyl)sulfonyl]-2-methyl-1-piperazinecarboxylate(may be prepared as described in Description 19) (3.24 g, 8.54 mmol) andTFA (7.00 ml, 91.0 mmol) in dry DCM (10 ml) was stirred at rt for 1 h,then concentrated under vacuum, azetroping with toluene (25 ml) to givean orange oil. This was redissolved in MeOH (10 ml) then applied to anSCX-2 cartridge (50 g), washing with MeOH. The product was eluted with2M NH₃ in MeOH; concentration under vacuum gave the title compound as apale orange oil (8.17 mmol).

m/z (API-ES) 280 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.06 (d, J=6.4 Hz, 3 H), 2.30 (dd,J=11.7, 10.4 Hz, 1 H), 2.67 (s, 3 H), 2.70 (td, J=11.6, 3.1 Hz, 1 H),2.81-2.88 (m, 1 H), 2.89 (td, J=11.5, 3.1 Hz, 1 H), 3.04 (dt, J=12.1,2.5 Hz, 1 H), 3.54-3.63 (m, 2 H), 7.60-7.64 (m, 2 H), 7.98 (d, J=8.6 Hz,1 H).

Description 21(3S)-3-methyl-1-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine

A solution of 4-[(trifluoromethyl)oxy]benzenesulfonyl chloride (3.25 g,12.48 mmol), 1,1-dimethylethyl (2S)-2-methyl-1-piperazinecarboxylate(2.5 g, 12.48 mmol) and DIPEA (4.58 ml, 26.2 mmol) in DCM (200 ml) wasstirred at room temperature overnight. The mixture was washed withsaturated aqueous NaHCO₃ then brine. The organics were concentratedunder vacuum, then re-dissolved in dioxane (200 ml). A 4M solution ofHCl in dioxane (20 ml) and water (0.5 ml) were added and the mixturestirred overnight. The mixture was concentrated under vacuum, applied toan SCX-2 cartridge (20 g) washing with MeOH and eluting with 0.5M NH₃ inMeOH; concentration under vacuum gave the title compound as a whitesolid (2.56 g).

m/z (API-ES) 325[M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.04 (d, J=6.4 Hz, 3 H), 1.93 (t,J=10.6 Hz, 1 H), 2.31 (td, J=11.2, 3.4 Hz, 1 H), 2.86-3.07 (m, 3 H),3.58-3.68 (m, 2 H), 7.37 (d, J=8.9 Hz, 2 H), 7.77-7.84 (m, 2 H)

Description 22(3R)-3-methyl-1-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine

To a solution of 1,1-dimethylethyl (2R)-2-methyl-1-piperazinecarboxylate(2.00 g, 9.99 mmol) in DCM (200 ml) was added DIPEA (3.66 ml, 20.97mmol) and then 4-[(trifluoromethyl)oxy]benzenesulfonyl chloride (1.69ml, 9.99 mmol) and the resulting mixture stirred at room temperature for90 min. The reaction mixture was then concentrated under vacuum andre-dissolved in 1,4-dioxane (100 ml). A 4M solution of HCl in1,4-dioxane (100 ml, 400 mmol) and a few drops of distilled water wereadded and the mixture stirred for 3 h. The reaction mixture wasconcentrated under vacuum, re-dissolved in DCM (200 ml) and washed with2M aqueous NaOH (2×50 ml). The organic layer was dried (MgSO₄), filteredand concentrated under vacuum. The residue was dissolved in ether andconcentrated under vacuum. The oil was dissolved in MeOH (150 ml),applied to an SCX cartridge (50 g), which was washed with MeOH, DCM andMeOH again. The product was eluted from the column with 2M ammonia inmethanol, DCM and then 2M ammonia in methanol; concentration undervacuum gave the title compound as a yellow transparent oil (2.92 g).

m/z (API-ES) 325 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.04 (d, J=6.4 Hz, 3 H), 1.93 (t,J=10.6 Hz, 1 H), 2.31 (td, J=11.2, 3.5 Hz, 1 H), 2.86-3.07 (m, 3 H),3.58-3.69 (m, 2 H), 7.37 (d, J=8.1 Hz, 2 H), 7.77-7.85 (m, 2 H)

Description 23 1,1-dimethylethyl(2S)-4-{[2-bromo-4-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (2S)-2-methyl-1-piperazinecarboxylate(1.20 g, 5.99 mmol) and DIPEA (5.45 ml, 31.2 mmol) in dry DCM (60 ml) at0° C. under Ar was added 2-bromo-4-(trifluoromethyl)benzenesulfonylchloride (2.04 g, 6.29 mmol) and the resulting clear solution stirred at0° C. for 2 h. EtOAc (100 ml) and saturated aqueous NaHCO₃ (100 ml) wereadded, the layers separated, then the organic layers washed with 2Maqueous HCl (100 ml) and passed through an hydrophobic frit. The solventwas removed to leave the title compound (2.36 g).

m/z (API-ES) 387 and 389 [M+H−100]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.02 (d, J=6.7 Hz, 3 H), 1.38 (s, 9 H),2.83 (td, J=12.3, 3.4 Hz, 1 H), 3.00 (dd, J=12.6, 3.8 Hz, 1 H), 3.07(td, J=12.8, 3.0 Hz, 1 H), 3.45 (d, J=12.6 Hz, 1 H), 3.73 (d, J=12.2 Hz,1 H), 3.81 (d, J=12.8 Hz, 1 H), 4.15-4.24 (m, 1 H), 7.99 (dd, J=8.2, 1.3Hz, 1 H), 8.18 (d, J=8.2 Hz, 1 H), 8.30 (d, J=1.1 Hz, 1 H)

Description 24(3S)-3-methyl-1-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}piperazine

A solution of 1,1-dimethylethyl(2S)-4-{[2-bromo-4-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-piperazinecarboxylate(may be prepared as described in Description 23) (1.00 g, 2.05 mmol),potassium carbonate (0.737 g, 5.34 mmol) in 1,4-dioxane (43 ml) werestirred for 5 min then trimethylboroxin (0.743 ml, 5.34 mmol) andPd(Ph₃P)₄ (0.403 g, 0.349 mmol) were added and the reaction mixtureheated at 100° C. overnight. EtOAc (100 ml) was added, then the mixturewas washed with aqueous sodium bicarbonate (100 ml), water (100 ml) andconcentrated under vacuum. Flash chromatography (silica; linear gradient(0-20%) EtOAc in isohexane) gave 1,1-dimethylethyl(2S)-2-methyl-4-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate(0.785 g). This material was re-dissolved in DCM (10 ml) and 1,4-dioxane(3 ml), then HCl in dioxane (5 eq) was added and the mixture stirred atroom temperature for 4 h. Aqueous sodium bicarbonate (20 ml) and EtOAc(20 ml) were added and the organic phase washed with aqueous sodiumbicarbonate (2×10 ml), brine (10 ml) and dried using a hydrophobic frit.The solvent was removed under vacuum. The residue was re-dissolved inDCM (10 ml) and 1,4-dioxane (3 ml), then 4M HCl in 1,4-dioxane (6.97 mL,27.9 mmol) added. The mixture was stirred at room temperature for 4 h.The solvent was evaporated under vacuum to give the title compound(0.615 g) as the hydrochloride salt.

m/z (API-ES) 323 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.22 (d, J=6.5 Hz, 3 H), 2.66 (s, 3 H),2.77 (dd, J=12.8, 10.5 Hz, 1 H), 2.93-3.11 (m, 2 H), 3.29-3.39 (m, 2 H),3.63-3.75 (m, 2 H), 7.84 (d, J=8.3 Hz, 1 H), 7.94 (s, 1 H), 8.03 (d,J=8.3 Hz, 1 H), 9.18 (br. s., 2 H)

Description 25 1,1-dimethylethyl(2S)-4-{[2-bromo-5-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl (2S)-2-methyl-1-piperazinecarboxylate(1.18 g, 4.98 mmol) in dichloromethane (40 ml) was added DIPEA (2.70 ml,15.45 mmol) and then 2-bromo-5-(trifluoromethyl)benzenesulfonyl chloride(1.613 g, 4.98 mmol). The reaction mixture was stirred for 1 h 20 min atroom temperature. The reaction mixture was then washed with water (50ml), dried on a phase separation cartridge and concentrated under vacuumto give the crude title compound (2.5 g) which was used directly in thenext step.

m/z (API-ES) 387+389 (1:1) [(M-Boc)+H]⁺

Description 26 1,1-dimethyl ethyl(2S)-2-methyl-4-{[2-methyl-5-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate

1,1-dimethylethyl(2S)-4-{[2-bromo-5-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-piperazinecarboxylate(may be prepared as described in Description 25) (2.5 g, 5.13 mmol),potassium carbonate (1.134 g, 8.21 mmol) in 1,4-dioxane (80 ml) werestirred for 5 min then trimethylboroxin (1.142 ml, 8.21 mmol) andPd(PPh₃)₄ (0.593 g, 0.513 mmol) were added and the reaction mixtureheated at 100° C. for 1.5 h. Further trimethylboroxin (0.5 mL) was addedand the reaction heated for 30 min before it was allowed to coolovernight.

The mixture was concentrated under vacuum then EtOAc (120 ml) added,washed with 200 ml of water, dried on a phase separation cartridge andevaporated under vacuum. The crude material (2.8 g) was purified viaBiotage (40+M silica column) using a gradient EtOAc/1-Hex from 0/100 to30/70. Desired fractions collected and concentrated under vacuum to givethe title compound (2.1 g).

m/z (API-ES) 323 [(M-Boc)+H]⁺

Description 27(3S)-3-methyl-1-{[2-methyl-5-(trifluoromethyl)phenyl]sulfonyl}piperazine

1,1-dimethylethyl(2S)-2-methyl-4-{[2-methyl-5-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate(may be prepared as described in Description 26) (2.1 g, 4.97 mmol) in1,4-Dioxane (50 mL) was treated by 4 M HCl in dioxane (6.21 mL, 24.85mmol). The reaction mixture was stirred overnight at room temperature.LCMS showed a 1:1 ratio between starting material and expected product.4 M HCl in dioxane (6.21 mL, 24.85 mmol) was added and the reactionmixture stirred for 4 h. LCMS showed about 10% of remaining startingmaterial. 4 M HCl in dioxane (6.21 mL, 24.85 mmol) was added and thereaction mixture stirred for 1 h.

The reaction mixture was then concentrated under vacuum, dissolved inEtOAc (100 ml) and extracted with 2N HCl (3×75 ml). 2N NaOH was added tothe aqueous until basic then product extracted with EtOAc, dried on aphase separation cartridge and concentrated under vacuum to give thetitle compound (1.16 g).

m/z (API-ES) 323 [M+H]⁺

Description 28 1,1-dimethylethyl4-{[2-bromo-5-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate

To a solution of 1,1-dimethylethyl 1-piperazinecarboxylate (1 g, 5.37mmol) in DCM (40 ml) was added DIPEA (1.969 ml, 11.28 mmol) and then2-bromo-5-(trifluoromethyl)benzenesulfonyl chloride (1.737 g, 5.37mmol). The mixture was stirred for 1 h 20 min at room temperature beforeit was washed with water (50 ml), dried on a phase separation cartridgeand concentrated under vacuum.

Crude product was dissolved in MeOH and eluted through a 10 g SCXcartridge (elution with MeOH), concentrated under vacuum to give (2.59g).

m/z (API-ES) 373+375 (1:1) [(M-Boc)+H]⁺

Description 29 1,1-dimethylethyl4-{[2-methyl-5-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate

1,1-dimethylethyl4-{[2-bromo-5-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate(may be prepared as described in Description 28) (2.59 g, 5.47 mmol),potassium carbonate (1.513 g, 10.94 mmol) in 1,4-dioxane (80 ml) werestirred for 5 min then trimethylboroxin (1.523 ml, 10.94 mmol) andPd(PPh₃)₄ (0.632 g, 0.547 mmol) were added and the reaction mixtureheated at 100° C. for 1.5 h. Further trimethylboroxin (0.5 mL) was addedand the mixture heated at 100° C. for 30 min before allowing to coolovernight. The mixture was concentrated under vacuum then EtOAc (150 ml)added, washed with 200 ml of water, dried on a phase separationcartridge and evaporated under vacuum. The crude material (3.1 g) waspurified via Biotage (40+M silica column) using a gradient EtOAc/1-hexfrom 10/90 to 30/70. Desired fractions were collected and concentratedunder vacuum to give the title compound (2.1 g).

m/z (API-ES) 309 [(M-Boc)+H]⁺

Description 301-{[2-methyl-5-(trifluoromethyl)phenyl]sulfonyl}piperazine

1,1-dimethylethyl4-{[2-methyl-5-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinecarboxylate(may be prepared as described in Description 29) (2.1 g, 5.14 mmol) in1,4-dioxane (50 mL) was treated by HCl 4M in dioxane (6.43 mL, 25.7mmol). The reaction mixture was stirred overnight at room temperature.LCMS showed a mixture of starting material and product so 8 ml of 4M HClin dioxane were added. LCMS after 2 h showed still some startingmaterial so 5 ml of 4M HCl in dioxane were added. LCMS after 2 h showedtraces of starting material.

The reaction mixture was concentrated under vacuum, dissolved in EtOAc(70 ml) and extracted with 2N HCl (3×80 ml). 2N NaOH was added to theaqueous layer until basic, then the product extracted with EtOAc, driedon a phase separation cartridge and concentrated under vacuum to givethe title compound (1.38 g).

m/z (API-ES) 309 [M+H]⁺

Description 31(2S)-4-{[2-bromo-4-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine

To a solution of(2S)-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine (may beprepared as described in Description 13) (200 mg, 0.912 mmol) in DCM (10mL) was added 2-bromo-4-(trifluoromethyl)benzenesulfonyl chloride (295mg, 0.912 mmol) followed by DIPEA (0.159 mL, 0.912 mmol). The reactionmixture was left stirring at room temperature for 15 h. The solvent wasremoved by evaporation and the crude residue was dissolved in DCM (30ml), washed with saturated sodium bicarbonate (40 ml), dried(hydrophobic frit) and evaporated under vacuum. The crude product waspurified by silica chromatography using a gradient EtOAc/iso-hexane from20/80 to 100/0. The desired fractions were combined and concentratedunder vacuum to give the title compound (216 mg).

m/z (API-ES) 506+508 (1:1) [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.34 (d, J=6.8 Hz, 3H), 2.60 (s, 3H),2.88 (td, J=12.0, 3.2 Hz, 1H), 3.08 (dd, J=12.8, 3.4 Hz, 1H), 3.40 (m,1H), 3.64 (d, J=12.8 Hz, 1H), 3.87 (d, J=12.4 Hz, 1H), 3.9-4.8 (brm,2H), 7.23 (d, J=8.0 Hz, 1H), 7.54 (d, J=8.0 Hz, 1H), 7.62 (d, J=8.4 Hz,1H), 8.02 (s, 1H), 8.21 (d, J=8.4 Hz, 1H), 8.51 (s, 1H)

Description 321-{[2-bromo-4-(trifluoromethyl)phenyl]sulfonyl}-4-[(6-methyl-3-pyridinyl)carbonyl]piperazine

This compound was prepared in a similar manner as the compound ofDescription 31 using the corresponding reactants.

m/z (API-ES) 492+494 (1:1) [M+H]⁺

Description 33 2-methyl-3-pyridinecarbonyl chloride

2-methyl-3-pyridinecarboxylic acid (20 g, 146 mmol) was dissolved inthionyl chloride (60 ml, 822 mmol) and stirred at room temperature for24 h. The reaction was concentrated under reduced pressure, to obtainthe title compound as a white solid (28.1 g, 146 mmol). Acyl chloridewas checked by quenching a sample in MeOH, LCMS showed methyl esterderivative. {[M+H]⁺=152}

Example 1(2S)-2-Methyl-1-[(6-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 2) (100 mg, 0.324 mmol) in DMF (5 ml) was added DIPEA(0.170 ml, 0.973 mmol), HOBT.H₂O (49.7 mg, 0.324 mmol), HBTU (123 mg,0.324 mmol) and 6-methyl-3-pyridinecarboxylic acid (44.5 mg, 0.324 mmol)and the reaction mixture was stirred overnight at room temperature. Thereaction mixture was evaporated in vacuo, DCM (50 ml) was added and thesolution was washed with NfaHCO₃ (5 ml×2). The organic layer was driedwith dried magnesium sulphate which was removed by filtration and thefiltrate evaporated to dryness in vacuo. The residual oil was dissolvedin 1:1 MeCN/DMSO (1.8 ml) and purified by MDAP in two batches. Thefractions containing the desired product were combined and evaporated todryness in vacuo. The residue was azeotroped with toluene to remove anyremaining water to yield the title compound (86 mg).

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.42 (d, J=6.8 Hz, 3 H) 2.56-2.58(m, 5 H) 3.28-3.47 (m, 1H) 3.55-3.64 (m, 1 H) 3.72-3.83 (m, 1 H)3.82-4.93 (m, 2 H) 7.21 (d, J=8.0 Hz, 1 H) 7.58 (dd, J=8.0, 2.0 Hz, 1 H)7.75-7.88 (m, 4 H) 8.44 (d, J=2.0 Hz, 1 H).

Example 2(2S)-2-Methyl-1-[(2-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride

To a solution of(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 2) (100 mg, 0.324 mmol) in DMF (5 ml) was added2-methyl-3-pyridinecarboxylic acid (44.5 mg, 0.324 mmol), HOBT.H₂O (49.7mg, 0.324 mmol) and HATU (123 mg, 0.324 mmol). Finally DIPEA (0.170 ml,0.973 mmol) was added and the reaction mixture was stirred at roomtemperature for 20 h. Solvent was removed by evaporation and MDAPpurification yielded the title compound as the formate salt. The formatesalt was suspended in saturated aqueous sodium bicarbonate and the freebase extracted in to DCM. Evaporation yielded the free base as a lightyellow oil. The oil was treated with 1M ethereal HCl to yield the titlecompound (118 mg) as a cream powder.

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) (NMR of free base; rotameric mixture) δppm 1.28-1.53 (m, 3 H), 1.98 (br. s., 1 H), 2.16-2.64 (m, 4 H),3.17-3.33 (m, 1 H), 3.38-3.98 (m, 3 H), 4.61-4.75 (m, 0.5 H), 4.99-5.15(m, 0.5 H), 7.10-7.23 (m, 1 H), 7.31-7.52 (m, 1 H), 7.84 (d, J=8.5 Hz, 2H), 7.87 (d, J=8.5 Hz, 2 H), 8.47-8.59 (m, 1 H).

Alternative Synthesis of(2S)-2-Methyl-1-[(2-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazineExample 2a

(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may beprepared as described in Description 2 or 2a) (30 g, 97 mmol) wasdissolved in tetrahydrofuran (300 mL) before sodium hydroxide 3M (97 mL,292 mmol) was added dropwise at 0° C. and the reaction stirred for 10min. 2-methyl-3-pyridinecarbonyl chloride (may be prepared as describedin Description 33) (26.2 g, 136 mmol) was added portionwise and theresulting mixture was stirred at room temperature for 10 min. The THFwas removed from the mixture under reduced pressure and the resultingsuspension was extracted with DCM (2×300 ml). The organic phase waswashed with brine, dried over Na₂SO₄, filtered and concentrated todryness to give the title compound (39.9 g).

m/z (API-ES) 428 [M+H]⁺

NMR Shows Rotameric Mixture:

¹H NMR (400 MHz, CDCl₃) δ ppm 1.33-1.50 (m, 3H), 2.20-2.62 (m, 5H), 3.27(m, 1H), 3.45-3.97 (m, 3H), 4.70+5.10 (m, 1H), 7.17 (m, 1H), 7.39 (m,1H), 7.85 (d, J=8.8 Hz, 2H), 7.89 (d, J=8.8 Hz, 2H), 8.56 (m, 1H).

Example 2b

(2S)-2-methyl-1-[(2-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 2 or 2a) (39.9 g, 93 mmol) wasdissolved in diethyl ether (500 ml). HCl 1.0M in ether (103 ml, 103mmol) was added dropwise (a solid crashed out from the solution) and themixture was stirred for 20 min. The white solid was recovered byfiltration and dried under vacuum at 70° C. for 36 h to give the titlecompound (41.48 g) as the hydrochloride salt.

m/z (API-ES) 428 [M+H]⁺

NMR shows rotameric mixture:

¹H NMR (400 MHz, DMSO) δ ppm 1.19-1.34 (m, 3H), 2.36-2.69 (m, 2H), 2.48(s, 3H), 3.18-3.26 (m, 1H), 3.34-3.47 (m, 1H), 3.49-3.63 (m, 1H),3.65-3.84 (m, 1H), 4.44+4.85 (m, 1H), 7.68 (m, 1H), 7.97 (d, J=8.4 Hz,2H), 8.07 (d, J=8.4 Hz, 2H), 8.88-8.21 (m, 1H), 8.68-8.73 (m, 1H).

Example 31-(3-Pyridinylcarbonyl)-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of 1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 1) (100 mg, 0.340 mmol) in DMF (5 ml) was added HOBT.H₂O(52.0 mg, 0.340 mmol), HBTU (129 mg, 0.340 mmol), 3-pyridinecarboxylicacid (41.8 mg, 0.340 mmol) and DIPEA (0.178 ml, 1.019 mmol). Thereaction mixture was stirred for 2 hours at room temperature. Reactionmixture was transferred to a 100 ml round bottom flask and was reducedto dryness in vacuo. The residue was dissolved in DCM (50 ml) and wastransferred to a separating funnel then washed with saturated NaHCO₃solution (5 ml), twice. The organic layer was collected and dried withdried magnesium sulphate. The solid was removed by filtration and thefiltrate collected in a 250 ml round bottom flask and reduced to drynessin vacuo. The residue was then dissolved in 1.8 ml 1:1 MeCN/DMSO andpurified by MDAP in 2 batches. The fractions containing desired productwere combined in a 250 ml round bottom flask and reduced in vacuo toyield the title compound (63 mg).

m/z (API-ES) 400 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 3.11 (br. s., 4 H), 3.38-4.15 (m, 4H), 7.37 (ddd, J=7.8, 4.9, 0.7 Hz, 1H), 7.71 (dt, J=7.9, 1.93 Hz, 1 H),7.80-7.95 (m, 4 H), 8.59 (d, J=1.5 Hz, 1 H), 8.68 (dd, J=4.9, 1.6 Hz, 1H).

Example 41-[(6-Methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of 1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 1) (100 mg, 0.340 mmol) in DMF (5 ml) was added HOBT.H₂O(52.0 mg, 0.340 mmol), HBTU (129 mg, 0.340 mmol),6-methyl-3-pyridinecarboxylic acid (46.6 mg, 0.340 mmol) and DIPEA (0.18ml, 1.02 mmol). The reaction mixture was stirred for 2 h at roomtemperature. Reaction mixture was transferred to a 100 ml round bottomflask and was reduced to dryness in vacuo. The residue was dissolved inDCM (50 ml) and was transferred to a separating funnel then washed withsaturated NaHCO₃ solution (5 ml), twice. The organic layer was collectedand dried with dried magnesium sulphate. The solid was removed byfiltration and the filtrate collected in a 250 ml round bottom flask andreduced to dryness in vacuo. The residue was then dissolved in 1.8 ml1:1 MeCN/DMSO and purified by MDAP in 2 batches. The fractionscontaining desired product were combined in a 250 ml round bottom flaskand reduced in vacuo to yield the title compound (69 mg).

m/z (API-ES) 414 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.59 (s, 3 H), 3.09 (m, 4 H),3.40-4.08 (m, 4 H), 7.21 (d, J=8.0 Hz, 1H), 7.60 (dd, J=8.0, 2.0 Hz, 1H), 7.83 (d, J=8.4 Hz, 2H), 7.89 (d, J=8.4 Hz, 2H), 8.47 (d, J=2.0 Hz, 1H).

Example 51-[(2-Methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of 1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 1) (100 mg, 0.340 mmol) in DMF (5 ml) was added HOBT.H₂O(52.0 mg, 0.340 mmol), HBTU (129 mg, 0.340 mmol),2-methyl-3-pyridinecarboxylic acid (46.6 mg, 0.340 mmol) and DIPEA(0.178 ml, 1.019 mmol). The reaction mixture was stirred for 2 hours atroom temperature.

Reaction mixture was transferred to a 100 ml round bottom flask and wasreduced to dryness in vacuo. The residue was dissolved in DCM (50 ml)and transferred to a separating funnel then was washed with saturatedNaHCO₃ solution (5 ml), twice. The organic layer was collected and driedwith dried magnesium sulphate. The solid was removed by filtration andthe filtrate collected in a 250 ml round bottom flask and reduced todryness in vacuo.

The residue was then dissolved in 1.8 ml 1:1 MeCN/DMSO and purified byMDAP in 2 batches. The fractions containing desired product werecombined in a 250 ml round bottom flask and reduced in vacuo to yieldthe title compound (107 mg).

m/z (API-ES) 414 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.45 (s, 3 H), 2.83-3.43 (m, 6 H),3.75-4.12 (m, 2 H), 7.12-7.20 (m, 1 H), 7.41 (dd, J=8.0, 2.0 Hz, 1 H),7.81-7.93 (m, 4 H), 8.55 (dd, J=5.0, 2.0 Hz, 1 H).

Example 64-{5-[(4-{[4-(Trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinyl}morpholine

To a solution of 1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 1) (80 mg, 0.272 mmol) in DMF (5 ml) were added6-(4-morpholinyl)-3-pyridinecarboxylic acid (56.6 mg, 0.272 mmol),HOBT.H₂O (41.6 mg, 0.272 mmol), HBTU (103 mg, 0.272 mmol) and DIPEA(0.142 ml, 0.816 mmol) and the reaction mixture was stirred at roomtemperature for 2 h. The DMF was evaporated in vacuo then 5 ml of DCMwere added and washed with saturated aqueous NaHCO₃ solution (5 ml),dried on a phase separation cartridge and evaporated in vacuo. The crudematerial was dissolved in MeCN/DMSO 1:1 and purified by MDAP. Thedesired fractions were collected and concentrated under vacuo giving thetitle compound (103 mg).

m/z (API-ES) 485 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 3.01-3.15 (m, 4 H), 3.53-3.62 (m, 4H), 3.70-3.79 (m, 4 H), 3.79-3.85 (m, 4 H), 6.60 (d, J=8.9 Hz, 1 H),7.58 (dd, J=8.9, 2.4 Hz, 1 H), 7.84 (d, J=8.3 Hz, 2 H), 7.89 (d, J=8.3Hz, 2 H), 8.19 (d, J=2.4 Hz, 1 H).

Example 74-[5-({(3S)-4-[(4-Chlorophenyl)sulfonyl]-3-methyl-1-piperazinyl}carbonyl)-2-pyridinyl]morpholine

To a suspension of (2S)-1-[(4-chlorophenyl)sulfonyl]-2-methylpiperazinehydrochloride (Description 4) (105 mg, 0.338 mmol), EDC (71.3 mg, 0.372mmol), HOBT.H₂O (56.9 mg, 0.372 mmol) and6-(4-morpholinyl)-3-pyridinecarboxylic acid (77 mg, 0.372 mmol) in DCM(5 ml) was added N-ethyl morpholine (0.090 mL, 0.710 mmol). The reactionwas stirred for 18 h at ambient temperature. To the reaction was addedwater (3 ml) and the organic layer collected via a hydrophobic frit. Theorganic layer was reduced in volume to approximately 2 ml then loadedonto a silica SP4 chromatography cartridge. The cartridge was elutedwith a gradient from 60% ethyl acetate in iso-hexane to ethyl acetatethen ethyl acetate. Fractions containing the desired product werecombined and reduced in vacuo to yield the title compound as a whitesolid (88 mg).

m/z (API-ES) 465 [M+H]⁺

Example 8(2S)-1-[(4-Chlorophenyl)sulfonyl]-2-methyl-4-[(6-methyl-3-pyridinyl)carbonyl]piperazine

To a suspension of (2S)-1-[(4-chlorophenyl)sulfonyl]-2-methylpiperazinehydrochloride (Description 4) (105 mg, 0.338 mmol), EDC (71.2 mg, 0.371mmol), HOBT.H₂O (56.9 mg, 0.371 mmol) and 6-methyl-3-pyridinecarboxylicacid (51.0 mg, 0.372 mmol) in DCM (5 ml) was added N-ethylmorpholine(0.090 ml, 0.710 mmol). The reaction was stirred for 18 h at ambienttemperature. To the reaction was added water (3 ml) and the organiclayer collected via a hydrophobic frit. The organic layer was reduced involume to approximately 2 ml then loaded onto a silica SP4chromatography cartridge. The cartridge was eluted with ethyl acetatethen a gradient from 0-10% (20% methanol in dichloromethane) in ethyl.Fractions containing the desired product were combined and reduced invacuo to yield the title compound as a white solid (55 mg).

m/z (API-ES) 394 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.0 (br s, 3 H), 2.6 (s, 3 H), 3.2(br s, 2 H), 3.7 (br s, 2 H), 4.0-4.8 (br m, 3 H), 7.2 (d, J=8.1 Hz, 1H), 7.5 (m, 2 H), 7.6 (d, J=2.2 Hz, 1 H), 7.7 (m, 2 H), 8.5 (d, J=1.5Hz, 1 H)

Example 9(2R)-2-Methyl-4-[(6-methyl-3-pyridinyl)carbonyl]-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazineformic acid salt

To a solution of 6-methyl-3-pyridinecarboxylic acid (47.7 mg, 0.348mmol) in DCM (2.00 ml) was added HATU (132 mg, 0.348 mmol) and DIPEA(0.152 ml, 0.870 mmol) and the mixture stirred for 15 min beforeaddition of(2R)-2-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride (Description 6) (100 mg, 0.290 mmol) in DMF (2 ml). Theresultant mixture was stirred for 16 h at room temperature then thereaction mixture was concentrated and the residue taken up in DMSO andpurified by MDAP. The collected fractions were concentrated in vacuo andtriturated with isohexane giving the title compound (77.7 mg) as a whitesolid.

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) rotameric mixture 6 ppm 0.74-1.17 (m, 3 H),2.53 (s, 3 H), 2.73-3.09 (m, 1 H), 3.34-4.56 (m, 6 H), 7.42 (d, J=8.0Hz, 1 H), 7.68-7.94 (m, 1 H), 7.95-8.10 (m, 4 H), 8.41-8.64 (m, 1 H).

Example 10(2R)-2-Methyl-4-[(2-methyl-3-pyridinyl)carbonyl]-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazineformic acid salt

To a solution of 2-methyl-3-pyridinecarboxylic acid (47.7 mg, 0.348mmol) in DCM (2.000 ml) was added HATU (132 mg, 0.348 mmol) and DIPEA(0.152 ml, 0.870 mmol) and the mixture stirred for 15 minutes beforeaddition of(2R)-2-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride (Description 6) (100 mg, 0.290 mmol) in DMF (2 ml). Theresultant mixture was stirred for 16 h at room temperature then thereaction mixture was then concentrated and the residue taken up in DMSOand purified by reverse phase MDAP. The collected fractions wereconcentrated in vacuo giving the title compound (80.7 mg) as a whitesolid.

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) rotameric mixture b ppm 0.79-1.10 (m, 3 H),2.23-2.48 (m, 3 H), 2.80-2.96 (m, 1 H), 3.00-3.13 (m, 1 H), 3.19-3.33(m, 1 H), 3.54-3.81 (m, 2 H), 3.97-4.49 (m, 2 H), 7.26-7.43 (m, 1 H),7.60-7.87 (m, 1 H), 7.93-8.12 (m, 4 H), 8.55 (td, J=5.1, 1.4 Hz, 1 H).

Example 11(2S)-2-Methyl-4-[(6-methyl-3-pyridinyl)carbonyl]-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazineformic acid salt

To a solution of(2S)-2-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride (Description 8) (100 mg, 0.270 mmol) in THF (5 ml) wasadded HOBT.H₂O (41.3 mg, 0.270 mmol), HBTU (102 mg, 0.270 mmol) and6-methyl-3-pyridinecarboxylic acid (40.7 mg, 0.297 mmol). The mixturewas stirred for 5 min before addition of DIPEA (0.118 ml, 0.674 mmol)and the resultant solution stirred at room temperature for 16 h. Themixture was then concentrated and the residue partitioned between DCM(10 ml) and water (10 ml), the layers were separated using a hydrophobicfrit, the organic layers were then concentrated to dryness and the crudematerial dissolved in DMSO and purified by MDAP giving the titlecompound (100.2 mg) as a colourless oil which solidified on standing.

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.04 (br. s., 3 H), 2.61 (s, 3 H),2.85-3.41 (m, 4 H), 3.62-3.84 (m, 1 H), 3.91-4.92 (m, 2 H), 7.25 (d,J=8.0 Hz, 1 H), 7.65 (dd, J=8.0, 2.1 Hz, 1 H), 7.80 (d, J=8.2 Hz, 2 H),7.94 (d, J=8.2 Hz, 2 H), 8.52 (s, 1 H).

Example 12(2S)-2-Methyl-4-[(2-methyl-3-pyridinyl)carbonyl]-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazineformic acid salt

To a solution of(2S)-2-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride (Description 8) (100 mg, 0.270 mmol) in THF (5 ml) wasadded HOBT.H₂O (41.3 mg, 0.270 mmol), HBTU (102 mg, 0.270 mmol) and2-methyl-3-pyridinecarboxylic acid (40.7 mg, 0.297 mmol). The mixturewas stirred for 5 min before addition of DIPEA (0.118 ml, 0.674 mmol)and the resultant solution stirred at room temperature for 16 h. Themixture was then concentrated and the residue partitioned between DCM(10 ml) and water (10 ml), the layers were separated using a hydrophobicfrit and the organic layers concentrated to dryness and the crudedissolved in DMSO and purified by MDAP giving the title compound (61.2mg) as a white solid.

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) rotameric mixture 6 ppm 0.88-1.19 (m, 3H), 2.41-2.62 (m, 3 H), 2.88-3.44 (m, 4 H), 3.58-3.88 (m, 1 H),4.03-4.44 (m, 1 H), 4.51-4.87 (m, 1 H), 7.13-7.26 (m, 1 H), 7.35-7.60(m, 1 H), 7.80 (d, J=8.3 Hz, 2 H), 7.93 (d, J=8.3 Hz, 2 H), 8.51-8.64(m, 1 H).

Example 135-[((2S)-2-Methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinecarbonitrile

To a solution of(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 2) (100 mg, 0.324 mmol) in DMF (5 ml) was added HOBT.H₂O(49.7 mg, 0.324 mmol), HBTU (123 mg, 0.324 mmol),6-cyano-3-pyridinecarboxylic acid (48.0 mg, 0.324 mmol) and DIPEA (0.170ml, 0.973 mmol) and the reaction mixture was stirred for 1 h at roomtemperature. The reaction mixture was reduced in vacuo. The residue wasdissolved in DCM (50 ml), transferred to a separating funnel and thesolution was washed with NaHCO₃ (5 ml), twice. The organic layer wasdried with magnesium sulphate which was removed by filtration and thefiltrate evaporated to dryness in vacuo. The residual oil was dissolvedin 1:1 MeCN/DMSO (1.8 ml) and purified by MDAP in two batches. Thefractions containing the desired product were combined and evaporated todryness in vacuo to yield the title compound (77 mg).

m/z (API-ES) 439 [M+H]⁺, 480 [M+H+41]⁺

Example 14(2S)-2-Methyl-1-{[6-(methyloxy)-3-pyridinyl]carbonyl}-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 2) (100 mg, 0.324 mmol) in DMF (5 ml) was added HOBT.H₂O(49.7 mg, 0.324 mmol), HBTU (123 mg, 0.324 mmol),6-(methyloxy)-3-pyridinecarboxylic acid (49.7 mg, 0.324 mmol) and DIPEA(0.170 ml, 0.973 mmol) and the reaction mixture was stirred for 1 h atroom temperature. The reaction mixture was evaporated in vacuo. Theresidue was dissolved in DCM (50 ml), transferred to a separating funneland the solution was washed with NaHCO₃ (5 ml), twice. The organic layerwas dried with magnesium sulphate which was removed by filtration andthe filtrate evaporated to dryness in vacuo. The residual oil wasdissolved in 1:1 MeCN/DMSO (1.8 ml) and purified by MDAP in two batches.The fractions containing the desired product were combined andevaporated to dryness in vacuo to yield the title compound (85 mg).

m/z (API-ES) 444 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 5 ppm 1.45 (d, J=6.8 Hz, 3 H) 2.29-2.41(m, 1 H) 2.43-2.56 (m, 1 H) 3.34-3.49 (m, 1 H) 3.55-3.66 (m, 1 H)3.75-3.85 (m, 1 H) 3.95 (s, 3 H) 4.01-4.25 (m, 1 H) 4.37-4.68 (m, 1 H)6.76 (dd, J=8.6, 0.7 Hz, 1 H) 7.59 (dd, J=8.6, 2.4 Hz, 1 H) 7.78-7.91(m, 4 H) 8.16 (d, J=2.4 Hz, 1 H)

Example 15(2S)-2-Methyl-1-{[2-(methyloxy)-3-pyridinyl]carbonyl}-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 2) (100 mg, 0.324 mmol) in DMF (5 ml) was added HOBT.H₂O(49.7 mg, 0.324 mmol), HBTU (123 mg, 0.324 mmol),2-(methyloxy)-3-pyridinecarboxylic acid (49.7 mg, 0.324 mmol) and DIPEA(0.170 ml, 0.973 mmol) and the reaction mixture was stirred for 1 h atroom temperature. The reaction mixture was reduced in vacuo. The residuewas dissolved in DCM (50 ml), transferred to a separating funnel and thesolution was washed with NaHCO₃ (5 ml), twice. The organic layer wasdried with magnesium sulphate which was removed by filtration and thefiltrate evaporated to dryness in vacuo. The residual oil was dissolvedin 1:1 MeCN/DMSO (1.8 ml) and purified by MDAP in two batches. Thefractions containing the desired product were combined and evaporated todryness in vacuo to yield the title compound (95 mg).

m/z (API-ES) 443 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) Rotameric mixture 5 ppm 1.23-1.55 (m, 3H), 2.06-2.79 (m, 2 H), 3.05-4.21 (m, 7 H), 4.53+5.14 (m, 1 H), 6.93(br. s., 1 H), 7.36-7.63 (m, 1 H), 7.69-7.95 (m, 4 H), 8.20 (d, J=4.8Hz, 1 H).

Example 16(2S)-2-Methyl-1-[(5-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 2) (100 mg, 0.324 mmol) in DMF (5 ml) was added HOBT.H₂O(49.7 mg, 0.324 mmol), HBTU (123 mg, 0.324 mmol),5-methyl-3-pyridinecarboxylic acid (44.5 mg, 0.324 mmol) and DIPEA(0.170 ml, 0.973 mmol) and the reaction mixture was stirred for 1 h atroom temperature. The reaction mixture was evaporated in vacuo. Theresidue was dissolved in DCM (50 ml), transferred to a separating funneland the solution was washed with aqueous NaHCO₃ (5 ml), twice. Theorganic layer was dried with magnesium sulphate which was removed byfiltration and the filtrate evaporated to dryness in vacuo. The residualoil was dissolved in 1:1 MeCN/DMSO (1.8 ml) and purified by MDAP in twobatches. The fractions containing the desired product were combined andevaporated to dryness in vacuo to the title compound (95 mg).

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.45 (d, J=6.9 Hz, 3 H), 2.34 (m,1H), 2.37 (s, 3H), 2.51 (m, 1H), 3.2-5.0 (m, 5 H), 7.50 (s, 1 H), 7.84(d, J=8.4 Hz, 2H), 7.88 (d, J=8.4 Hz, 2H), 8.35 (d, J=1.6 Hz, 1 H), 8.50(d, J=1.6 Hz, 1 H).

Example 173-Methyl-4-({(3S)-3-methyl-4-[(6-methyl-3-pyridinyl)carbonyl]-1-piperazinyl}sulfonyl)benzonitrile

To a solution of3-methyl-4-{[(3S)-3-methyl-1-piperazinyl]sulfonyl}benzonitrile(Description 11) (75 mg, 0.268 mmol), 6-methyl-3-pyridinecarboxylic acid(40.5 mg, 0.295 mmol) and DIPEA (0.070 ml, 0.403 mmol) in dry DMF (3 ml)at room temperature under Ar was added HATU (122 mg, 0.322 mmol) and theresulting yellow solution stirred at room temperature for 1 h.Concentration in vacuo gave a yellow oil, that was purified by MDAPpurification; concentration of the desired fractions gave a clear film(78.8 mg). Flash chromatography (silica; Flash 12S; linear gradient(1-8%) [2M NH₃ in MeOH] in DCM) gave the title compound as a clear film(54.5 mg) that became a white solid on standing in vacuo (1 mbar) for 1hour.

m/z (API-ES) 399 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.36 (d, J=6.8 Hz, 3 H), 2.59 (s, 3H), 2.67 (s, 3 H), 2.72 (td, J=11.8, 3.2 Hz, 1 H), 2.90 (dd, J=12.3, 3.2Hz, 1 H), 3.28-3.43 (m, 1 H), 3.58 (d, J=12.2 Hz, 1 H), 3.72 (d, J=11.7Hz, 1 H), 3.88-4.82 (m, 2 H), 7.22 (d, J=7.9 Hz, 1 H), 7.60 (dd, J=8.0,2.3 Hz, 1 H), 7.62-7.66 (m, 2 H), 7.95 (d, J=8.7 Hz, 1H), 8.49 (d, J=1.7Hz, 1 H).

Example 18(2S)-2-Methyl-1-[(4-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a solution of(3S)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 2) (100 mg, 0.324 mmol) in DMF (5 ml) was added HOBT.H₂O(49.7 mg, 0.324 mmol), HBTU (123 mg, 0.324 mmol),4-methyl-3-pyridinecarboxylic acid (44.5 mg, 0.324 mmol) and DIPEA(0.170 ml, 0.973 mmol) and the reaction mixture was stirred for 1 h atroom temperature. The reaction mixture was reduced in vacuo. The residuewas dissolved in DCM (50 ml), transferred to a separating funnel and thesolution was washed with aqueous NaHCO₃ (5 ml), twice. The organic layerwas dried with dried magnesium sulphate which was removed by filtrationand the filtrate evaporated to dryness in vacuo. The residual oil wasdissolved in 1:1 MeCN/DMSO (1.8 ml) and purified by MDAP in two batches.The fractions containing the desired product were combined andevaporated to dryness in vacuo. The residue was then dissolved indiethyl ether (50 ml) and transferred to a 100 ml round bottom flask andreduced to dryness in vacuo to yield the title compound (67 mg).

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) (rotameric mixture) δ ppm 1.26-1.52 (m, 3H), 2.60-2.64 (m, 10 H), 7.43-7.62

(m, 1 H), 7.87 (d, J=6.5 Hz, 4 H), 8.44-8.66 (m, 2 H).

Example 19(2R)-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazineformic acid salt (1:1)

To a solution of(3R)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 12) (80 mg, 0.259 mmol) in DMF (4 ml) was added6-methyl-3-pyridinecarboxylic acid (35.6 mg, 0.259 mmol), HOBT.H₂O (39.7mg, 0.259 mmol), HBTU (98 mg, 0.259 mmol) and DIPEA (0.136 ml, 0.778mmol) and the reaction mixture was stirred at room temperature for 1 h.The DMF was evaporated in vacuo then 5 ml of DCM were added and washedwith saturated NaHCO₃ solution (5 ml), dried on a phase separationcartridge and evaporated in vacuo. The crude material was dissolved inMeCN/DMSO 1:1 and purified by MDAP to give the title compound (93 mg).

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.45 (d, J=6.9 Hz, 3 H) 2.37 (td,J=11.9, 2.9 Hz, 1 H) 2.52 (dd, J=11.4, 2.4 Hz, 1 H) 2.61 (s, 3 H)3.33-3.49 (m, 1 H) 3.62 (d, J=11.8 Hz, 1 H) 3.75-3.87 (m, 1 H) 4.00-4.90(m, 2 H) 7.25 (s, 1 H) 7.65 (dd, J=8.0, 2.2 Hz, 1 H) 7.80-7.91 (m, 4 H)8.47 (d, J=1.8 Hz, 1 H)

Example 20(2R)-2-methyl-1-[(2-methyl-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazineformic acid salt (1:1)

To a solution of(3R)-3-methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(Description 12) (80 mg, 0.259 mmol) in DMF (4 ml) was added2-methyl-3-pyridinecarboxylic acid (35.6 mg, 0.259 mmol), HOBT.H₂O (39.7mg, 0.259 mmol), HBTU (98 mg, 0.259 mmol) and DIPEA (0.136 ml, 0.778mmol) and the reaction mixture was stirred at room temperature for 1 h.The DMF was evaporated under vacuum, 5 ml of DCM added and then washedwith saturated NaHCO₃ solution (5 ml), dried on a phase separationcartridge and evaporated under vacuo. The crude material was dissolvedin MeCN/DMSO 1:1 and purified by MDAP to give the title compound (75mg).

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) (rotameric mixture) δ ppm 1.28-1.41 (m,1.5 H), 1.41-1.55 (m, 1.5 H), 2.19-2.34 (m, 1 H), 2.37-2.51 (m, 3 H),2.51-2.66 (m, 1 H), 3.17-3.36 (m, 1 H), 3.38-3.62 (m, 1 H), 3.62-3.85(m, 1.5 H), 3.85-4.01 (m, 0.5 H), 4.61-4.76 (m, 0.5 H), 5.01-5.16 (m,0.5 H), 7.13-7.26 (m, 1 H), 7.34-7.59 (m, 1 H), 7.79-7.93 (m, 4 H), 8.54(d, J=3.5 Hz, 1 H).

Example 21(2S)-2-Methyl-1-[(6-methyl-3-pyridinyl)carbonyl]-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine

To a solution of(2S)-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine (Description13) (100 mg, 0.456 mmol) in DMF (10 ml) was added4-[(trifluoromethyl)oxy]benzenesulfonyl chloride (143 mg, 0.547 mmol).Finally DIPEA (0.239 ml, 1.368 mmol) was added and the reaction mixturewas stirred at room temperature for 20 h. Solvent was removed byevaporation, the residue was dissolved in ethyl acetate and the solutionextracted with saturated aqueous NaHCO₃. The organic layer was driedover MgSO₄, filtered and evaporated to dryness and the residue waspurified by MDAP to yield the title compound (32 mg) as a white powder.

m/z (API-ES) 444 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.45 (d, J=6.8 Hz, 3 H) 2.15-4.94(m, 7 H) 2.65 (s, 3 H) 7.31 (d, J=8.0 Hz, 1 H) 7.39 (dd, J=8.8, 0.8 Hz,2 H) 7.71 (dd, J=8.0, 2.2 Hz, 1 H) 7.76-7.83 (m, 2 H) 8.56 (d, J=1.8 Hz,1 H)

Example 22(2S)-4-({4-[(Difluoromethyl)oxy]phenyl}sulfonyl)-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine

To a solution of(2S)-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine (Description13) (100 mg, 0.456 mmol) in DMF (10 ml) was added4-[(difluoromethyl)oxy]benzenesulfonyl chloride (133 mg, 0.547 mmol).Finally DIPEA (0.239 ml, 1.368 mmol) was added and the reaction mixturewas stirred at room temperature for 20 h. Solvent was removed byevaporation, the residue was dissolved in ethyl acetate and the solutionwashed with saturated aqueous NaHCO₃. The organic layer was dried overMgSO₄, filtered and evaporated to dryness and the residue was purifiedby MDAP to yield the title compound (72 mg) as a white powder.

m/z (API-ES) 426 [M+H]⁺ ^(.)

1H NMR (400 MHz, CHLOROFORM-d) ppm 1.43 (d, J=6.8 Hz, 3 H) 2.12-4.80 (m,7 H) 2.60 (s, 3 H) 6.63 (t, J=72.2 Hz, 1 H) 7.23 (d, J=8.0 Hz, 1 H)7.25-7.33 (m, 2 H) 7.61 (dd, J=8.0, 2.3 Hz, 1 H) 7.71-7.79 (m, 2 H) 8.48(d, J=1.8 Hz, 1 H)

Example 231-[(6-Methyl-3-pyridinyl)carbonyl]-4-({4-[(trifluoromethyl)oxy]phenyl}sulfonyl)piperazine

To a solution of 1-[(6-methyl-3-pyridinyl)carbonyl]piperazine (may beprepared as described in Description 14) (100 mg, 0.487 mmol) in DMF (10ml) was added 4-[(trifluoromethyl)oxy]benzenesulfonyl chloride (152 mg,0.585 mmol). Finally DIPEA (0.255 ml, 1.462 mmol) was added and thereaction mixture was stirred at room temperature for 20 h. Solvent wasremoved by evaporation, the residue was dissolved in ethyl acetate andthe solution extracted with saturated aqueous NaHCO₃. The organic layerwas dried over MgSO₄, filtered and evaporated to dryness and the residuewas purified by MDAP to yield the title compound (42 mg) as a whitepowder.

m/z (API-ES) 430 [M+H]⁺

1H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.63 (s, 3 H) 2.91-4.10 (m, 8 H)7.25-7.30 (m, 1 H) 7.40 (dd, J=8.9, 0.85 Hz, 2 H) 7.69 (dd, J=8.0, 2.3Hz, 1 H) 7.78-7.84 (m, 2 H) 8.54 (d, J=1.8 Hz, 1 H).

Example 24(2S)-1-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

HATU (460 mg, 1.21 mmol) was added to a solution of6-chloro-2-methyl-3-pyridinecarboxylic acid (commercially available,e.g. from Anichem, or may be prepared according to known methods) (173mg, 1.01 mmol) in DMF (4 ml) and the mixture was treated with DIPEA(0.440 ml, 2.52 mmol). This mixture was stirred for ca. 10 min atambient temperature.(3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may beprepared as described in Description 2) (371 mg, 1.20 mmol) was thenadded and stirring was continued for one hour. The reaction mixture waspartitioned between DCM and sat aq. NaHCO₃ solution (20 ml each). Thelayers were separated and the aqueous was washed with further DCM (2×20ml). The combined organic layers were concentrated to leave a dark browngum. Purification by silica chromatography (Biotage SP4, 25S cartridge),eluting with 12-100% ethyl acetate in isohexane, gave the title compound(456 mg) as a pale yellow gum.

m/z (API-ES) 462/464 [M+H]⁺ (Cl isotopes)

Example 254-({(3S)-4-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile

HATU (425 mg, 1.12 mmol) was added to a solution of6-chloro-2-methyl-3-pyridinecarboxylic acid (commercially available,e.g. from Anichem, or may be prepared according to known methods) (160mg, 0.93 mmol) in DMF (3 ml) and the mixture was treated with DIPEA(0.407 ml, 2.33 mmol). This mixture was stirred for ca. 10 min atambient temperature.3-Methyl-4-{[(3S)-3-methyl-1-piperazinyl]sulfonyl}benzonitrile (may beprepared as described in Description 11) (313 mg, 1.12 mmol) was addedas a solution in DMF (2 ml) and stirring was continued for ca. 1 hour.The reaction mixture was partitioned between DCM and sat aq. NaHCO₃solution (20 ml each). The layers were separated and the aqueous waswashed with further DCM (2×20 ml). The combined organic layers weredried (hydrophobic frit) and concentrated to leave a dark brown gum.Purification by silica chromatography (Biotage SP4, 25S cartridge),eluting with 12-100% ethyl acetate in isohexane, gave the title compoundas a pale cream foam (376 mg).

m/z (API-ES) 433/435 [M+H]⁺ (Cl isotopes)

Example 26(2S)-1-[(6-Chloro-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

HATU (458 mg, 1.21 mmol) was added to a solution of6-chloro-3-pyridinecarboxylic acid (supplied by Aldrich) (174 mg, 1.10mmol) in DMF (4 ml) and the mixture was treated with DIPEA (0.437 ml,2.50 mmol). This mixture was stirred for ca. 10 min at ambienttemperature.(3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may beprepared as described in Description 2) (308 mg, 1.0 mmol) was added andstirring was continued for 1.25 h. The reaction mixture was partitionedbetween DCM and saturated aqueous NaHCO₃ solution (20 ml each). Thelayers were separated and the aqueous layer was washed with further DCM(2×20 ml). The combined organic layers were concentrated to leave a darkbrown gum. Purification by silica chromatography (Biotage SP4, 25Scartridge), eluting with 12-100% ethyl acetate in pentane, gave thetitle compound (439 mg) as a pale yellow gum.

m/z (API-ES) 448/450 [M+H]⁺ (Cl isotopes)

Example 27(2S)-1-[(6-Fluoro-4-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

HATU (440 mg, 1.16 mmol) was added to a solution of6-fluoro-4-methyl-3-pyridinecarboxylic acid (supplied by FrontierScientific) (150 mg, 0.97 mmol) in DMF (4 ml) and the mixture wastreated with DIPEA (0.422 ml, 2.42 mmol). This mixture was stirred forca. 10 min at ambient temperature.(3S)-3-Methyl-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may beprepared as described in Description 2) (358 mg, 1.16 mmol) was addedand stirring was continued for 1.25 h. The reaction mixture waspartitioned between DCM and saturated aqueous NaHCO₃ solution (20 mleach). The layers were separated and the aqueous was washed with furtherDCM (2×20 ml). The combined organic layers were concentrated to leave adark brown gum. Purification by silica chromatography (Biotage SP4, 25Scartridge), eluting with 12-100% ethyl acetate in hexanes, gave thetitle compound (432 mg) as a yellow gum.

m/z (API-ES) 446 [M+H]⁺

Example 28(2S)-1-[(5-Bromo-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

HATU (458 mg, 1.21 mmol) was added to a solution of5-bromo-3-pyridinecarboxylic acid (supplied by Aldrich) (203 mg, 1.01mmol) in DMF (4 ml) and the mixture was treated with DIPEA (0.438 ml,2.51 mmol). This mixture was stirred for ca. 10 min at ambienttemperature.(3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may beprepared as described in Description 2) (372 mg, 1.21 mmol) was addedand stirring was continued for 1.5 h. The reaction mixture waspartitioned between DCM and sat aq. NaHCO₃ solution (20 ml each). Thelayers were separated and the aqueous was washed with further DCM (2×20ml). The combined organic layers were concentrated to leave an darkbrown gum.

Purification by silica chromatography (Biotage SP4, 25S cartridge),eluting with 12-100% ethyl acetate in isohexane, gave the title compound(496 mg) as a yellow gum, which became a yellow foam when dried invacuo.

m/z (API-ES) 492/494 [M+H]⁺ (Br isotopes)

Example 29(2S)-1-[(2,6-Dimethyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

2,6-Dimethyl-3-pyridinecarboxylic acid (GSK1770624A, Atlantic) (98 mg,0.65 mmol) and HATU (247 mg, 0.65 mmol) were suspended in DMF (2 ml) andDIPEA (0.170 ml, 0.97 mmol) was added. This mixture was stirred for 40min at ambient temperature.(3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may beprepared as described in Description 2) (100 mg, 0.32 mmol) was addedand stirring continued for 3 h. The reaction mixture was partitionedbetween DCM and sat aq. NaHCO₃ solution (10 ml each). The layers wereseparated and the aqueous was washed with further DCM (2×5 ml). Thecombined organic layers were concentrated to leave a brown oil. This waspurified by MDAP to give the title compound (92 mg) as an orange solid.

m/z (API-ES) 442 [M+H]⁺

Example 304-[((3S)-4-{[6-(Dimethylamino)-2-methyl-3-pyridinyl]carbonyl}-3-methyl-1-piperazinyl)sulfonyl]-3-methylbenzonitrilehydrochloride

4-({(3S)-4-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(may be prepared as described in Example 25) (60 mg, 0.14 mmol) wasweighed into a microwave vial, and suspended in isopropanol (1 ml).Dimethylamine, 2M in methanol (0.7 ml, 1.4 mmol) was added and themixture was heated in the microwave to 100° C. for 30 min with stirring.LCMS analysis showed incomplete reaction (˜13% conversion). The mixturewas treated with further dimethylamine, 2M in methanol (0.35 ml, 0.7mmol) and heated with stirring in the microwave at 100° C. for 6 h,after which LCMS analysis indicated >50% conversion. The reactionmixture was concentrated to give the crude material as a yellow gumwhich was purified by MDAP to give the free base of the product as acolourless gum (25 mg).

m/z (API-ES) 442 [M+H]⁺

The material was dissolved in THF (0.5 ml), treated with ethereal. HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (17.6 mg) as acolourless solid

m/z (API-ES) 442 [M+H]⁺

Example 31 N,N,6-Trimethyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 24) (65 mg, 0.14 mmol) wasweighed into a microwave vial, and suspended in isopropanol (0.7 ml).Dimethylamine, 2M in methanol (0.7 ml, 1.40 mmol) was added, and themixture was stirred briefly to give a clear solution. This was heated inthe microwave to 120° C. for 4 h with stirring. The reaction mixture wasconcentrated to give the crude material as a yellow gum, which waspurified by MDAP to give the free base of the title compound as acolourless gum (47 mg).

m/z (API-ES) 471 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.37 (br s, 3 H), 2.23-2.35 (m, 4H), 2.42-2.53 (m, 1 H), 3.08 (s, 6 H), 3.24-3.50 (m, 1 H), 3.54-3.66 (m,1 H), 3.68-3.84 (m, 1 H), 4.0-4.5 (v br, 1 H), 4.8-5.2 (v br, 1 H), 6.29(d, J=8.5 Hz, 1 H), 7.14 (d, J=8.5 Hz, 1H), 7.80-7.89 (m, 4 H).

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (37.6 mg) as acolourless solid.

m/z (API-ES) 471 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.23 (br s, 3 H), 2.30 (br s, 3 H),2.33-2.46 (m, 1H), 2.50-2.59 (m, 1 H), 3.14 (s, 6 H), 3.0-4.0 (m,obscured by water, 3 H), 4.2-4.5 (v br, 1 H), 4.6-4.9 (v br, 1 H), 6.82(br s, 1 H), 7.59 (br s, 1 H), 7.95 (d, J=8.5 Hz, 2 H), 8.06 (d, J=8.5Hz, 2 H).

Example 32N,N-Diethyl-6-methyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 24) (55 mg, 0.12 mmol) wasweighed into a microwave vial, and suspended in isopropanol (1.2 ml).The diethylamine (0.124 ml, 1.19 mmol) was added and the clear solutionwas heated in the microwave to 120° C. for 5 h with stirring.

LCMS analysis showed very poor conversion (˜5%). Further diethylamine(0.25 ml, 2.39 mmol) was added, the vial was resealed and was heatedwith stirring to 140° C. in the microwave for 5 h, after which LCMSanalysis showed ˜24% conversion. Further diethylamine (0.25 ml, 2.39mmol) was added, the vial was resealed and was heated with stirring to140° C. in the microwave for 15 h, giving ca. 65% conversion by LCMSanalysis. The reaction mixture was concentrated to give a dark gum (68mg). This was purified by MDAP to give the free base of the titlecompound as a colourless gum (26 mg).

m/z (API-ES) 499 [M+H]⁺

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (19 mg) as acolourless solid.

m/z (API-ES) 499 [M+H]⁺

Example 334-[((3S)-4-{[6-(Diethylamino)-2-methyl-3-pyridinyl]carbonyl}-3-methyl-1-piperazinyl)sulfonyl]-3-methylbenzonitrilehydrochloride

4-({(3S)-4-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(may be prepared as described in Example 25) (49 mg, 0.11 mmol) wasweighed into a microwave vial, and suspended in isopropanol (1.1 ml).Diethylamine (0.237 ml, 2.26 mmol) was added and the mixture was heatedin the microwave to 140° C. for 15 h with stirring. LCMS analysis showed˜34% conversion. The reaction was treated with further diethylamine(0.237 ml, 2.26 mmol), and returned to the microwave at 140° C., set for18 h. However, the microwave stopped during this run after an unknownreaction time, and LCMS analysis showed little additional conversion.Further diethylamine (0.118 ml, 1.13 mmol) was added and the reactionwas again heated with stirring in the microwave at 140° C. for 16.5 h.LCMS analysis now showed ˜65% conversion.

The reaction mixture was concentrated to give the crude material as adark brown gum (68 mg). This was purified by MDAP to give the free baseof the title compound as a pale brown gum (26 mg).

m/z (API-ES) 470 [M+H]⁺

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (24 mg) as a palebrown solid.

m/z (API-ES) 470 [M+H]⁺

Example 344-{6-Methyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinyl}morpholinehydrochloride

(2S)-1-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 24) (67 mg, 0.15 mmol) wasweighed into a microwave vial, and dissolved in isopropanol (1.4 ml).Morpholine (0.253 ml, 2.90 mmol) was added and the clear solution washeated in the microwave to 120° C. for 4 h with stirring. LCMS analysisshowed ˜40% conversion. Further morpholine (0.126 ml, 1.45 mmol) wasadded and the stirred reaction was heated to 120° C. for 6 h. LCMSanalysis showed ˜79% conversion. The reaction mixture was concentratedto give the crude material as a colourless gum (87 mg). This waspurified by MDAP to give the free base of the title compound as acolourless gum (44 mg).

m/z (API-ES) 513 [M+H]⁺

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (40 mg) as acolourless solid.

m/z (API-ES) 513 [M+H]⁺

Example 353-Methyl-4-[((3S)-3-methyl-4-{[2-methyl-6-(4-morpholinyl)-3-pyridinyl]carbonyl}-1-piperazinyl)sulfonyl]benzonitrilehydrochloride

4-({(3S)-4-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(may be prepared as described in Example 25) (55 mg, 0.13 mmol) wasweighed into a microwave vial, and suspended in isopropanol (1.3 ml).Morpholine (0.221 ml, 2.54 mmol) was added and the mixture was heated inthe microwave to 120° C. for 12 h with stirring. LCMS analysisindicated >65% conversion. The reaction mixture was concentrated to givethe crude material as a pale yellow gum (78 mg). This was purified byMDAP to give the free base of the title compound as a colourless gum (31mg).

m/z (API-ES) 484 [M+H]⁺

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to the title compound (26 mg) as a colourlesssolid.

m/z (API-ES) 484 [M+H]⁺

Example 36N-Ethyl-6-methyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 24) (67 mg, 0.15 mmol) wasweighed into a microwave vial, and dissolved in isopropanol (0.7 ml).Ethylamine, 2.0M in methanol (1.5 ml, 3.0 mmol) was added, and the clearsolution was heated in the microwave to 120° C. for 6 h with stirring.LCMS analysis showed <20% conversion. The mixture was treated withfurther ethylamine, 2.0M in methanol (0.75 ml, 1.50 mmol) and returnedto the microwave for 18 h at 120° C. with stirring. LCMS analysis showed˜50% conversion. The reaction mixture was treated with furtherethylamine, 2.0M in methanol (1.5 ml, 3.0 mmol), and again heated in themicrowave for 18 h at 120° C. with stirring. LCMS now showed adequateconversion, >65%. The reaction mixture was concentrated to give thecrude material as a yellow gum (76 mg). This was purified by MDAP togive the free base of the title compound as a pale yellow gum (34 mg).

m/z (API-ES) 471 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.10 (t, J=7 Hz, 3 H), 1.15-1.28 (m, 3H), 2.10 (s, 3 H), 2.28-2.38 (m, 1 H), 2.46-2.53 (m, 1 H), 3.21 (quint,J=6.5 Hz, 2 H) 3.10-3.76 (m, obscured by water, 3 H), 3.8-4.3 (v br, 1H), 4.5-5.0 (v br, 1 H), 6.22 (d, J=8.5 Hz, 1 H), 6.65 (t, J=6 Hz, N—H),7.13 (d, J=8.5 Hz, 1 H), 7.95 (d, J=8 Hz, 2 H), 8.05 (d, J=8 Hz, 2 H).

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting pale yellow gum wastriturated with ether, then dried, to give the title compound (25 mg) asa pale yellow solid.

m/z (API-ES) 471 [M+H]⁺

Example 37N,6-Dimethyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 24) (66 mg, 0.14 mmol) wasweighed into a microwave vial, and treated with methylamine, 2 molar inTHF (1.5 ml, 3.00 mmol). The clear solution was heated in the microwaveto 120° C. for 24 h with stirring.

LCMS analysis showed only ˜16% conversion. The mixture was treated withfurther methylamine, 2 molar in THF (0.75 ml, 1.50 mmol) and returned tothe microwave for 16 h at 140° C. with stirring. LCMS analysis showed˜23% conversion. The reaction mixture was concentrated under a stream ofargon. The crude residue was dissolved in methanol (0.5 ml). Thissolution was treated with further methylamine, 2 molar in THF (1.5 ml,3.00 mmol) and returned to the microwave for 24 h at 150° C. withstirring. LCMS analysis now showed complete conversion to product. Thereaction mixture was concentrated to give the crude material as a yellowgum (77 mg).

This was purified by MDAP (High pH system) to give the free base of thetitle compound as a colourless gum (49 mg).

m/z (API-ES) 457 [M+H]⁺

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.17-1.25 (m, 3 H), 2.12 (s, 3 H),2.28-2.37 (m, 1 H), 2.47-2.53 (m, 1H, obscured by DMSO), 2.74 (d, J=4.5Hz, 3 H) 3.08-3.45 (m, 1 H), 3.45-3.55 (m, 1 H), 3.56-3.75 (m, 1 H),3.9-4.3 (v br, 1 H), 4.5-4.9 (v br, 1 H), 6.22 (d, J=8.5 Hz, 1 H),6.62-6.68 (m, N—H), 7.15 (d, J=8.5 Hz, 1 H), 7.95 (d, J=8 Hz, 2 H), 8.05(d, J=8 Hz, 2 H).

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (49 mg) as acolourless solid.

m/z (API-ES) 457 [M+H]⁺

Example 383-Methyl-4-[((3S)-3-methyl-4-{[2-methyl-6-(methylamino)-3-pyridinyl]carbonyl}-1-piperazinyl)sulfonyl]benzonitrile

4-({(3S)-4-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(may be prepared as described in Example 25) (62 mg, 0.14 mmol) wasweighed into a microwave vial with stirrer and treated with methylamine,2 molar in THF (1.5 ml, 3.00 mmol). The vial was heated in the microwaveto 140° C. for 12 h with stirring. LCMS analysis showed only ˜13%conversion. The reaction mixture was treated with further methylamine, 2molar in THF (0.75 ml, 1.50 mmol) and heated to 150° C. in the microwavefor 24 h., then left to stand three days at ambient temperature. LCMSanalysis showed ˜52% conversion. The reaction mixture was concentratedunder argon flow to decrease the total volume by about 0.75 ml. It wastreated with further methylamine, 2 molar in THF (0.75 ml, 1.50 mmol).The vial was sealed and the reaction was heated in the microwave withstirring at 150° C. for 24 h. LCMS analysis showed ˜60% conversion. Thereaction mixture was concentrated under argon flow to give the crudematerial as a yellow gum (87 mg). This was purified by MDAP (High pHsystem) to give a colourless gum (25 mg). However, LCMS analysis showedthe presence of an impurity. The material was again purified by MDAP(High pH system, extended run) to give a colourless gum (17 mg). Duringconversion to the hydrochloride salt, this compound proved slightlysensitive to acid, as LCMS analysis showed an impurity. The material wasagain purified by MDAP (High pH system, extended run) to give acolourless gum, which was re-dissolved in methanol, treated with waterand reconcentrated to give the title compound (14 mg) as a colourlesssolid.

m/z (API-ES) 428 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.23-1.35 (m, 3 H), 2.30 (s, 3 H),2.61-2.73 (m, 4 H), 2.86-2.93 (m, 1 H), 2.91 (d, J=5 Hz, 3 H), 3.17-3.34(m, 1 H), 3.51-3.62 (m, 1 H), 3.63-3.75 (m, 1 H), 3.9-4.4 (v br, 1 H),4.68-4.75 (m, N—H), 4.9-5.2 (v br, 1 H), 6.21 (d, J=8.5 Hz, 1 H), 7.20(d, J=8.5 Hz, 1 H), 7.62-7.66 (m, 2 H), 7.96 (d, J=8 Hz, 1 H).

Example 39(2S)-1-{[6-(1-Azetidinyl)-2-methyl-3-pyridinyl]carbonyl}-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride

(2S)-1-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 24) (66 mg, 0.14 mmol) wastransferred into a microwave vial as a solution in isopropanol (1.4 ml).Azetidine (0.163 ml, 2.42 mmol) was added and the clear solution washeated in the microwave to 120° C. for 18 h with stirring. LCMS analysisshowed >80% conversion. The reaction mixture was concentrated to givethe crude material as a colourless gum (˜200 mg). This was purified byMDAP to give the free base of the title compound as a brown gum (45 mg).

m/z (API-ES) 483 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.28-1.43 (m, 3 H), 2.12-2.55 (m, 7H), 3.20-3.52 (m, 1 H), 3.54-3.68 (m, 1 H), 3.69-3.90 (m, 1 H), 3.9-4.1(v br, 1 H), 4.04 (t, J=7 Hz, 4 H), 4.2-5.2 (v br, 1 H), 6.05 (d, J=8.5Hz, 1 H), 7.14 (br, 1 H), 7.80-7.90 (m, 4 H).

The material was dissolved in THF (0.5 ml) and treated with 4M HCl indioxan (0.1 ml) and reconcentrated. The resulting brown gum wastriturated with ether, then dried, to give the title compound (46 mg) asa solid.

m/z (API-ES) 483 [M+H]⁺

Example 404-[((38)-4-{[6-(1-Azetidinyl)-2-methyl-3-pyridinyl]carbonyl}-3-methyl-1-piperazinyl)sulfonyl]-3-methylbenzonitrilehydrochloride

4-({(3S)-4-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(may be prepared as described in Example 25) (65 mg, 0.15 mmol) wasweighed into a microwave vial and suspended in isopropanol (1.5 ml).Azetidine (0.203 ml, 3.01 mmol) was added and the mixture was heated inthe microwave to 120° C. for 18 h with stirring. LCMS analysisshowed >80% conversion. The reaction mixture was concentrated to givethe crude material as a colourless gum (273 mg). This was purified byMDAP to give the free base of the title compound as a colourless gum (32mg).

m/z (API-ES) 454 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.21-1.32 (m, 3 H), 2.20-2.42 (m, 4H), 2.39 (quintet, J=7.5 Hz, 2 H), 2.59-2.72 (m, 4 H), 2.82-2.95 (m, 1H), 3.18-3.32 (m, 1 H), 3.50-3.61 (m, 1 H), 3.62-3.75 (m, 1 H), 4.05 (t,J=7.5 Hz, 4 H), 4.2-5.2 (v br, 1 H), 6.07 (d, J=8.5 Hz, 1 H), 7.17 (d,J=8 Hz, 1 H), 7.60-7.65 (m, 2 H), 7.96 (d, J=8.5 Hz, 1 H).

The material was dissolved in THF (0.5 ml) and treated with 4M HCl indioxan (0.2 ml) and reconcentrated. The resulting colourless gum wastriturated with ether, then dried, to give the title compound (29 mg) asa colourless solid.

m/z (API-ES) 454 [M+H]⁺

Example 41N,N-Dimethyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-Chloro-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 26) (67 mg, 0.15 mmol) wasweighed into a microwave vial, suspended in isopropanol (0.75 ml) andtreated with dimethylamine, 2M in methanol (0.75 ml, 1.50 mmol). Themixture was heated in the microwave to 120° C. for 18 h with stirring.LCMS analysis showed clean conversion to the product. The reactionmixture was concentrated to give the crude material as a pale yellowgum/solid. This was purified by MDAP (High pH system) to give the freebase of the title compound as a colourless gum (61 mg).

m/z (API-ES) 457 [M+H]⁺

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (73 mg) as acolourless solid.

m/z (API-ES) 457 [M+H]⁺

Example 424-{5-[((2S)-2-Methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinyl}morpholinehydrochloride

(2S)-1-[(6-Chloro-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may be prepared as described inExample 26) (67 mg, 0.15 mmol) was weighed into a microwave vial,suspended in isopropanol (1.5 ml) and treated with morpholine (0.261 ml,2.99 mmol). The mixture was heated in the microwave to 120° C. for 18 hwith stirring. LCMS analysis showed clean conversion to product. Thereaction mixture was concentrated to give the crude material as acolourless gum. This was purified by MDAP (High pH system) to give thefree base of the title compound as a colourless gum (69 mg).

m/z (API-ES) 499 [M+H]⁺

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (77 mg) as acolourless solid.

m/z (API-ES) 499 [M+H]⁺

Example 43N-Ethyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-Chloro-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 26) (67 mg, 0.15 mmol) wasweighed into a microwave vial, and treated with ethylamine, 2.0M inmethanol (1.5 ml, 3.0 mmol). The clear solution was heated in themicrowave to 120° C. for 18 h with stirring. LCMS analysis showedcomplete conversion. The reaction mixture was concentrated to give thecrude material as a yellow gum (76 mg). This was purified by MDAP togive the free base of the title compound as a colourless gum (59 mg).

m/z (API-ES) 457 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.11 (t, J=7.5 Hz, 3 H), 1.24 (d, J=6.5Hz, 3 H), 2.38 (td, J=6.5, 3.5 Hz, 1 H), 2.48-2.54 (m, obscured by DMSO,1 H), 3.20-3.30 (m, 2 H) 3.30-3.40 (m, obscured by water, 1 H), 3.48 (d,J=12 Hz, 1 H), 3.66 (d, J=12 Hz, 1H), 3.89-3.99 (m, 1 H), 4.36-4.50 (m,1 H), 6.40 (d, J=8 Hz, 1 H), 6.96 (t, J=5 Hz, N—H), 7.36 (dd, J=8, 2 Hz,1 H), 7.94 (d, J=8 Hz, 2 H), 8.01 (d, J=2 Hz, 1 H), 8.05 (d, J=8 Hz, 2H).

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (56 mg) as a creamsolid.

m/z (API-ES) 457 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.19 (t, J=7.5 Hz, 3 H), 1.27 (d, J=6.5Hz, 3 H), 2.37-2.47 (m, 1 H), 2.56 (dd, J=12, 3.5 Hz, 1 H), 3.20-3.80(m, obscured by water, H), 3.75-4.0 (v br, 1 H), 4.20-4.50 (v br, 1 H),6.96 (d, J=8.5 Hz, 1 H), 7.76 (dd, J=8.5 Hz, 1 H), 7.93-7.99 (m, 3 H),8.06 (d, J=8 Hz, 2 H), 8.7-9.2 (v br, N—H).

Example 44Methyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

2S)-1-[(6-Chloro-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 26) (67 mg, 0.15 mmol) wasweighed into a microwave vial, and treated with methylamine, 2 molar inTHF (1.5 ml, 3.00 mmol). The clear solution was heated in the microwaveto 120° C. for 12 h with stirring. LCMS analysis showed ˜60% conversion.The mixture was treated with further methylamine, 2 molar in THF (0.75ml, 1.50 mmol) and returned to the microwave for 16 h at 120° C. withstirring. LCMS analysis showed >71% conversion. The reaction mixture wasconcentrated to give the crude material as a yellow gum (73 mg). Thiswas purified by MDAP (High pH system) to give the free base of the titlecompound as a colourless gum (35 mg).

m/z (API-ES) 443 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.44 (d, J=6.5 Hz, 3 H), 2.34 (td,J=12, 3.5 Hz, 1 H), 2.48 (dd, J=12, 3.5 Hz, 1 H), 2.94 (d, J=6, 3 H),3.40 (td, J=13, 3 Hz, 1 H), 3.59 (d, J=12 Hz, 1 H), 3.78 (br d, J=12 Hz,1 H), 4.11-4.21 (m, 1 H), 4.53-4.64 (m, 1 H), 4.80-4.88 (m, N—H), 6.36(d, J=8.5 Hz, 1 H), 7.48 (dd, J=8.5, 2 Hz, 1 H), 7.80-7.89 (m, 4 H),8.10 (d, J=2 Hz, 1 H).

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (29 mg) as anoff-white solid.

m/z (API-ES) 443 [M+H]⁺

Example 45(2S)-1-{[6-(1-Azetidinyl)-3-pyridinyl]carbonyl}-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride

(2S)-1-[(6-Chloro-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 26) (69 mg, 0.154 mmol) wastransferred into a microwave vial as a solution in isopropanol (1.5 ml).Azetidine (0.208 ml, 3.08 mmol) was added and the clear solution washeated in the microwave to 120° C. for 12 h with stirring. LCMS analysisshowed complete conversion. The reaction mixture was concentrated togive the crude material as a colourless gum (206 mg). This was purifiedby MDAP (High pH system) to give the free base of the title compound asa colourless gum (65 mg).

m/z (API-ES) 469 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.42 (d, J=6.5 Hz, 3 H), 2.33 (td,J=12, 3Hz, 1 H), 2.39-2.50 (m, 3 H), 3.38 (td, J=12.5, 3 Hz, 1 H),3.55-3.62 (m, 1 H), 3.73-3.80 (m, 1 H), 4.08 (t, J=7.5 Hz, 4 H),4.10-4.20 (m, 1 H), 4.52-4.63 (br, 1 H), 6.21 (d, J=8.5 Hz, 1 H), 7.49(dd, J=8, 2 Hz, 1 H), 7.79-7.91 (m, 4 H), 8.12 (d, J=2 Hz, 1 H).

The material was dissolved in THF (0.5 ml) and treated with 4M HCl indioxan (0.2 ml) and reconcentrated. The resulting colourless gum wastriturated with ether, then dried, to give the title compound (79 mg) asa colourless solid.

m/z (API-ES) 469 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.42 (d, J=6.5 Hz, 3 H), 2.38 (td,J=12, 3 Hz, 1 H), 2.48-2.64 (m, 3 H), 3.38-3.50 (m, 1 H), 3.57-3.67 (m,1 H), 3.68-3.87 (m, 5 H), 3.92-4.06 (br, 1 H), 4.4-4.6 (obscured by H₂,1 H), 6.48 (d, J=8.5 Hz, 1 H), 7.76 (dd, J=8, 2 Hz, 1 H), 7.82-7.91 (m,4 H), 7.97 (d, J=2 Hz, 1 H).

Example 46N,N,4-Trimethyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-Fluoro-4-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 27) (62 mg, 0.14 mmol) wasweighed into a microwave vial, and dissolved in isopropanol (0.7 ml).The dimethylamine, 2M in methanol (0.7 ml, 1.40 mmol) was added, and themixture was heated in the microwave to 120° C. for 4 h with stirring.LCMS analysis showed clean conversion to product. The reaction mixturewas concentrated to give the crude material as a pale yellow gum (80mg). This was purified by MDAP (High pH system) to give the free base ofthe title compound as a colourless gum (56 mg).

m/z (API-ES) 471 [M+H]⁺

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (56 mg) as acolourless solid.

m/z (API-ES) 471 [M+H]⁺

Example 47 4-{4-Methyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinyl}morpholinehydrochloride

(2S)-1-[(6-fluoro-4-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 27) (60 mg, 0.14 mmol) wasweighed into a microwave vial, and dissolved in isopropanol (1.4 ml).Morpholine (0.236 ml, 2.71 mmol) was added, and the mixture was heatedin the microwave to 120° C. for 5 h with stirring. LCMS analysis showedclean conversion to product. The reaction mixture was concentrated togive the crude material as a colourless gum/glass (85 mg). This waspurified by MDAP (High pH system) to give the free base of the titlecompound as a colourless gum (57 mg).

m/z (API-ES) 513 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.32-1.45 (m, 3 H), 2.19 (s, 3 H),2.25-2.36 (m, 1 H), 2.42-2.53 (m, 1 H), 3.28-3.41 (m, 1 H), 3.47-3.54(m, 4 H), 3.56-3.66 (m, 1 H), 3.70-3.88 (m, 5 H), 4.0-4.50 (v br, 1 H),4.8-5.1 (v br, 1 H), 6.44 (s, 1 H), 7.80-7.93 (m, 5 H).

The material was dissolved in THF (0.5 ml) and treated with ethereal HCl(0.5 ml) and reconcentrated. The resulting colourless gum was trituratedwith ether, then dried, to give the title compound (54 mg) as acolourless solid.

m/z (API-ES) 513 [M+H]⁺

Example 48

N,4-Dimethyl-5-[((2S)-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinaminehydrochloride

(2S)-1-[(6-Fluoro-4-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 27) (67 mg, 0.15 mmol) wasweighed into a microwave vial. The methylamine, 2 molar in THF (1.5 ml,3.00 mmol) was added, and the mixture was heated in the microwave to120° C. for 18 h with stirring.

LCMS analysis showed clean conversion to product. The reaction mixturewas concentrated to give the crude material as a pale yellow gum (70mg). This was purified by MDAP (High pH system) to give the free base ofthe title compound as a colourless gum (60 mg).

m/z (API-ES) 457 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.32-1.43 (m, 3 H), 2.16 (s, 3 H),2.30 (br t, J=11 Hz, 1 H), 2.43-2.52 (m, 1 H), 2.91 (d, J=5 Hz, 3 H),3.27-3.41 (m, 1 H), 3.54-3.65 (m, 1 H), 3.70-3.84 (m, 1 H), 4.0-4.50 (vbr, 1 H), 4.65 (q, J=4.5 Hz, N—H), 4.7-5.2 (v br, 1 H), 6.20 (s, 1 H),7.70 (s, 1 H), 7.80-7.89 (m, 4 H).

The material was dissolved in THF (0.5 ml) and treated with 4M HCl indioxan (0.1 ml) and reconcentrated. The resulting colourless gum wastriturated with ether, then dried, to give the title compound (63 mg).

m/z (API-ES) 457 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.18-1.32 (m, 3 H), 2.16 (s, 3 H),2.38-2.50 (m, 1 H), 2.53-2.65 (m, 1 H), 2.93 (s, 3 H), 3.10-3.75 (m,obscured by water, 3 H), 4.3-4.5 (v br, 1 H), 4.7-5.0 (v br, 1 H), 6.88(br, 1 H), 7.87 (br s, 1 H), 7.96 (d, J=7.5 Hz, 2 H), 8.06 (d, J=7.5 Hz,2 H), 8.4-9.2 (v br, N—H).

Example 49(2S)-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]-4-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride

(2S)-4-{[2-bromo-4-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine(may be prepared as described in Description 31) (216 mg, 0.427 mmol),potassium carbonate (153 mg, 1.109 mmol) in 1,4-dioxane (9 ml) werestirred for 5 min then trimethylboroxin (0.154 ml, 1.109 mmol) andPd(PPh₃)₄ (84 mg, 0.073 mmol) were added and the reaction mixture heatedat 100° C. for 1 h. The reaction mixture was concentrated under vacuum,dissolved in MeOH and filtered through a 5 g SCX column. LCMS showedstill some triphenylphosphine oxide and another small impurity so theproduct was dissolved in EtOAc (40 ml) and extracted with HCl 2N (40ml). 2 N NaOH was added to the aqueous layer until pH12 and productextracted with EtOAc (100 ml). The organic phase was dried on a phaseseparation cartridge and concentrated under vacuum. LCMS of the firstEtOAc layer showed it contained some of the product so was extractedagain with 2 N HCl (40 ml). 2 N NaOH was added to the aqueous layeruntil pH12 and product extracted with EtOAc (100 ml). The organic layerwas dried on a phase separation cartridge and the two batches werecombined and concentrated under vacuum to give the free base of theproduct. The product was suspended in DCM, 0.5 ml of 1N HCl in ether wasadded and the solvent was evaporated to give the title compound (193mg).

m/z (API-ES) 442 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.22 (d, J=6.8 Hz, 3H), 2.61 (s, 3H),2.66 (s, 3H), 2.77 (m, 1H), 2.94 (d, J=9.2 Hz, 1H), 3.2-4.2 (5H hiddenunder broad water peak), 7.60 (d, J=8.0 Hz, 1H), 7.81 (d, J=8.4 Hz, 1H),7.92 (s, 1H), 7.99 (d, J=8.4 Hz, 1H), 8.04 (d, J=8.0 Hz, 1H), 8.65 (s,1H).

Example 504-({(3S)-4-[(6-iodo-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile

To a solution of3-methyl-4-{[(3S)-3-methyl-1-piperazinyl]sulfonyl}benzonitrile (may beprepared as described in Description 11) (300 mg, 0.950 mmol),6-iodo-3-pyridinecarboxylic acid (prepared from 6-chloronicotinic acid,according to the literature procedure: G. R. Newkome, C. N. Moorfieldand B. Sabbaghian, J. Org. Chem., 1986, 51, 953-954.) (248 mg, 0.997mmol), HOBT (175 mg, 1.14 mmol) and Et₃N (0.331 ml, 2.38 mmol) in dryDMF (5 ml) at room temperature under Ar was added HBTU (432 mg, 1.14mmol) and the resulting brown solution stirred at room temperature for16 h. The mixture was concentrated under vacuum to leave a red gum (743mg). Flash chromatography (silica; Flash 25S; linear gradient (6-50%)ethyl acetate in isohexane) gave the title compound as a pale yellowfoam (301 mg).

m/z (API-ES) 511 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.37 (d, J=6.8 Hz, 3 H), 2.68 (s, 3H), 2.69-2.78 (m, 1 H), 2.87-2.96 (m, 1 H), 3.37 (br. s., 1 H), 3.61 (d,J=12.4 Hz, 1 H), 3.74 (d, J=12.2 Hz, 1 H), 4.49 (br. s., 2 H), 7.35 (dd,J=8.1, 2.5 Hz, 1 H), 7.62-7.67 (br s, 2 H), 7.82 (dd, J=8.1, 0.6 Hz, 1H), 7.96 (d, J=8.6 Hz, 1 H), 8.36 (d, J=2.0 Hz, 1H)

Example 511-[(6-chloro-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

To a suspension of 6-chloro nicotinic acid (1.76 g, 11.2 mmol) in DCM(50 ml) at 0° C. was added EDC.HCl (2.93 g, 15.3 mmol), HOBt (2.34 g,15.3 mmol) and DIPEA (7.52 ml, 40.8 mmol) and the mixture stirred for 20min. 1-{[4-(Trifluoromethyl)phenyl]sulfonyl}piperazine (may be preparedas described in Description 1) (3.00 g, 10.2 mmol) was added and thesolution allowed to warm to room temperature, then stirred overnight.The mixture was diluted with DCM (20 ml), washed with water (5×20 ml),then the organic layers dried (Na₂SO₄) and concentrated under vacuum toleave the crude compound. Flash chromatography (silica; 60% EtOAc inpet. ether) gave the title compound as a white solid (2.20 g).

m/z (API-ES) 434 [M+H]⁺

¹H NMR (400 MHz, CDCl₃) δ ppm 3.10 (br s, 4H), 3.77 (br s), 7.39 (d,1H), 7.66 (d, 1H), 7.85 (d, 2H), 7.89 (d, 2H), 8.38 (s, 1H).

Example 523-methyl-4-({(2S)-2-methyl-4-[(6-methyl-3-pyridinyl)carbonyl]-1-piperazinyl}sulfonyl)benzonitrilehydrochloride

To a solution of3-methyl-4-{[(2S)-2-methyl-1-piperazinyl]sulfonyl}benzonitrile (may beprepared as described in Description 17) (75.0 mg, 0.268 mmol),6-methyl-3-pyridinecarboxylic acid (44.2 mg, 0.322 mmol) and DIPEA(0.070 ml, 0.403 mmol) in dry DMF (3 ml) at room temperature under Arwas added HATU (112 mg, 0.295 mmol) and the resulting yellow solutionstirred at room temperature for 1 h. Concentration under vacuum gave ayellow oil, that was purified by MDAP; concentration of the desiredfractions with a 2M aqueous HCl solution (2 ml) gave a clear film (110mg). Flash chromatography (silica; Flash 12M; linear gradient (1.2-10%)[2M NH₃ in MeOH] in DCM) gave the title compound as a clear film (88.8mg, 0.215 mmol), that became a white solid on standing under vacuum (2mbar) for 18 h.

m/z (API-ES) 399 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.18 (br s, 3 H), 2.59 (s, 3 H),2.62 (s, 3 H), 2.81-3.86 (m, 5 H), 4.09 (br s, 1 H), 4.32-4.91 (m, 1 H),7.23 (d, J=7.9 Hz, 1 H), 7.60-7.66 (m, 3 H), 8.08 (d, J=8.6 Hz, 1 H),8.52 (d, J=1.8 Hz, 1 H)

Example 534-({(3S)-4-[(6-ethyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrilehydrochloride

Ar was bubbled through a solution of4-({(3S)-4-[(6-iodo-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(may be prepared as described in Example 50) (50.0 mg, 0.098 mmol) indry 1,4-dioxane (3 ml) for 30 min, then PdCl₂ (dppf) (7.17 mg, 9.80μmol) and diethylzinc (1M in hexanes, 0.118 ml, 0.118 mmol) were added,and the solution heated at 100° C. for 30 min. The solution was cooledto room temperature, then partitioned between a saturated aqueous NaHCO₃solution (5 ml) and DCM (25 ml). The mixture was shaken, then applied toa phase separator; the organic layers were concentrated under vacuum toleave a dark brown oil (59 mg). Purification by MDAP and concentrationof the desired fractions gave a clear film (21 mg). The film wasre-dissolved in THF (1 ml), treated with HCl (1M in ether, 0.051 ml,0.051 mmol) and dried at 35° C. under a stream of Ar to leave the titlecompound as a light brown gum, that became a pale yellow powder ontrituration with ether (35.8 mg).

m/z (API-ES) 413 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.32 (t, J=7.6 Hz, 3 H), 1.38 (d,J=6.8 Hz, 3 H), 2.68 (s, 3 H), 2.73 (td, J=12.3, 3.1 Hz, 1 H), 2.87 (q,J=7.7 Hz, 2 H), 2.90 (m, 1 H), 3.37 (m, 1 H), 3.60 (d, J=12.3 Hz, 1 H),3.74 (d, J=11.8 Hz, 1 H), 3.81-4.80 (m, 2 H), 7.26 (m, 1 H), 7.61-7.66(m, 2 H), 7.68 (dd, J=8.1, 2.2 Hz, 1 H), 7.96 (d, J=8.6 Hz, 1 H), 8.55(d, J=1.8 Hz, 1 H)

Example 543-Methyl-4-[((3S)-3-methyl-4-{[6-(1-methylethyl)-3-pyridinyl]carbonyl}-1-piperazinyl)sulfonyl]benzonitrilehydrochloride

Ar was bubbled through a solution of4-({(3S)-4-[(6-iodo-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(may be prepared as described in Example 50) (50.0 mg, 0.098 mmol) indry 1,4-dioxane (3 ml) for 30 min, then PdCl₂ (dppf) (7.17 mg, 9.80μmol) and diisopropylzinc (1M in toluene, 0.118 ml, 0.118 mmol) wereadded and the solution heated at 100° C. for 30 min. The solution wascooled to room temperature, then partitioned between a saturated aqueousNaHCO₃ solution (5 ml) and DCM (25 ml). The mixture was shaken, thenapplied to a phase separator; the organic layers were concentrated undervacuum to leave a dark brown oil (64 mg). Purification by MDAP andconcentration of the desired fractions gave a pale yellow film. The filmwas re-dissolved in THF (1 ml) then treated with HCl (1M in ether, 0.045ml, 0.045 mmol) and the solvent removed at 35° C. under a stream of Arto leave the title compound as a pale brown gum, that became a paleyellow powder on trituration with ether (27.9 mg).

m/z (API-ES) 427 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.31 (d, J=6.9 Hz, 6 H), 1.38 (d,J=6.7 Hz, 3 H), 2.68 (s, 3 H), 2.74 (td, J=12.4, 3.1 Hz, 1 H), 2.91 (dd,J=12.2, 2.7 Hz, 1 H), 3.11 (spt, J=7.0 Hz, 1 H), 3.37 (m, 1 H), 3.60 (d,J=12.2 Hz, 1 H), 3.75 (d, J=12.3 Hz, 1 H), 3.87-4.81 (m, 2 H), 7.26 (m,1 H), 7.61-7.69 (m, 3 H), 7.96 (d, J=8.7 Hz, 1 H), 8.54 (d, J=1.7 Hz, 1H)

Example 55(2S)-2-methyl-1-[(2-methyl-3-pyridinyl)carbonyl]-4-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}piperazinehydrochloride

To a solution of(3S)-3-methyl-1-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Description 24) (100 mg, 0.279 mmol)and 2-methyl-3-pyridinecarboxylic acid (38.2 mg, 0.279 mmol) in DMF (5mL), HOBt (46.9 mg, 0.307 mmol), N-ethylmorpholine (0.078 mL, 0.613mmol) and HBTU (116 mg, 0.307 mmol) were added and the reaction mixturestirred at room temperature for 60 h. The mixture was concentrated undervacuum, then partitioned between water (10 ml) and DCM (10 ml). Theaqueous was extracted with DCM (10 ml) and the organic layer separatedby hydrophobic frit. The organic layers were concentrated under vacuumto leave a yellow oil that was re-dissolved in 1:1 DMSO/MeCN (1.7 ml),split into two batches and purified by MDAP. The relevant fractions werecombined and concentrated under vacuum to leave yellow oil (91 mg). Thiswas re-dissolved in THF (5 ml) and treated with 1M HCl in ether (0.2ml). The solvent was removed at 40° C. under a flow of Ar to leave thetitle compound as a white solid (101 mg).

m/z (API-ES) 442 [M+H]⁺

¹H NMR (400 MHz, METHANOL-d₄) δ ppm 1.26-1.44 (m, 3 H), 2.64-2.79 (m, 6H), 2.83-2.98 (m, 1 H), 3.10 (d, J=10.1 Hz, 1 H), 3.37-3.76 (m, 3 H),3.80-3.95 (m, 1 H), 4.95-5.03 (m, 1 H), 7.72 (d, J=6.5 Hz, 1 H), 7.76(s, 1 H), 7.96 (br. s., 1 H), 8.06 (d, J=6.7 Hz, 1 H), 8.49 (br. s., 1H), 8.80 (br. s., 1 H).

Example 56N,N-diethyl-5-[(4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinamine

A solution of1-[(6-chloro-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 51) (100 mg, 0.23 mmol) anddiethylamine (0.45 ml, 2.3 mmol) in isopropanol (3 ml) was irradiated to180° C. for 1 h. The mixture was concentrated, then the residuere-dissolved in EtOAc (100 ml), washed with water (25 ml), brine (25ml), dried (Na₂SO₄) and concentrated under vacuum to leave an orangesolid (110 mg). Flash chromatography (silica; 40% EtOAc in pet. ether)gave the title compound as a solid (35 mg).

m/z (API-ES) 471 [M+H]⁺

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.08 (t, 6H), 3.04 (br s, 4H), 3.51 (m,4H), 3.59 (br s, 4H), 6.55 (d, 1H), 7.48 (dd, 1H), 7.96 (d, 2H), 8.04(d, 2H), 8.11 (d, 1H).

Example 57N,N-dimethyl-5-[(4-{[4-(trifluoromethyl)phenyl]sulfonyl}-1-piperazinyl)carbonyl]-2-pyridinamine

A solution of1-[(6-chloro-3-pyridinyl)carbonyl]-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 51) (300 mg, 0.692 mmol) anddimethylamine (2M, 0.35 ml, 6.921 mmol) was irradiated to 100° C. for 3h. The mixture was concentrated under vacuum, re-dissolved in DCM (20ml), washed with water (3×10 ml), dried (Na₂SO₄) and concentrated undervacuum to leave the crude product. Flash chromatography (silica; 50%EtOAc in pet. ether) gave the title compound as a solid (169 mg).

m/z (API-ES) 443 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 3.08 (m, 4H), 3.13 (s, 6H), 3.67(m, 4H), 6.48 (d, 1H), 7.56 (dd, 1H), 7.84 (d, 2H), 7.87 (d, 2H), 8.18(d, 1H).

Examples 58 to 68

The compounds of Table 1 were prepared in a similar manner as thecompound of Example 1 using the corresponding reactants.

TABLE 1 Example m/z (API- no. Name Structure ES) [M + H]⁺ 58(2R)-2-methyl-1-[(2-methyl- 3-pyridinyl)carbonyl]-4-({4-[(trifluoromethyl)oxy]phenyl} sulfonyl)piperazine

444 59 (2S)-2-methyl-1-[(6-methyl- 3-pyridinyl)carbonyl]-4-{[2-methyl-5- (trifluoromethyl)phenyl]sulfon- yl}piperazine

442 60 (2S)-2-methyl-1-[(2-methyl- 3-pyridinyl)carbonyl]-4-{[2-methyl-5- (trifluoromethyl)phenyl]sulfon- yl}piperazine

442 61 1-[(6-methyl-3- pyridinyl)carbonyl]-4-{[2- methyl-5-(trifluoromethyl)phenyl]sulfon- yl}piperazine

428 62 1-[(2-methyl-3- pyridinyl)carbonyl]-4-{[2- methyl-5-(trifluoromethyl)phenyl]sulfon- yl}piperazine

428 63 3-methyl-4-({(3R)-3-methyl- 4-[(6-methyl-3-pyridinyl)carbonyl]-1- piperazinyl}sulfonyl)benzo- nitrile

399 64 (2S)-2-methyl-1-[(2-methyl- 3-pyridinyl)carbonyl]-4-({4-[(trifluoromethyl)oxy]phenyl} sulfonyl)piperazine

444 65 (2R)-2-methyl-1-[(2-methyl- 3-pyridinyl)carbonyl]-4-({4-[(trifluoromethyl)oxy]phenyl} sulfonyl)piperazine

444 66 5-[(4-{[4- (trifluoromethyl)phenyl]sulfon-yl}-1-piperazinyl)carbonyl]-2- pyridinamine

415 67 4-({(3S)-4-[(2,6-dimethyl-3- pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3- methylbenzonitrile

413 68 4-({(3S)-4-[(4,6-dimethyl-3- pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3- methylbenzonitrile

413

Examples 69 to 71

The compounds of Table 2 were prepared in a similar manner as thecompounds of Example 56 and 57 using the corresponding reactants.

TABLE 2 m/z (API- Example ES) no. Name Structure [M + H]⁺ 691-{[6-(1-pyrrolidinyl)-3- pyridinyl]carbonyl}-4-{[4-(trifluoromethyl)phenyl]sulfon- yl}piperazine

469 70 N-(tetrahydro-2H-pyran-4- yl)-5-[(4-{[4-(trifluoromethyl)phenyl]sulfon- yl}-1-piperazinyl)carbonyl]-2-pyridinamine

499 71 4-[((3S)-4-{[6- (dimethylamino)-3- pyridinyl]carbonyl}-3-methyl-1-piperazinyl)sulfonyl]-3- methylbenzonitrile

428

Examples 72 and 73

The compounds of Table 3 were prepared in a similar manner as thecompound of Example 22 using the corresponding reactants.

TABLE 3 Example m/z (API- no. Name Structure ES) [M + H]⁺ 724-({(3S)-3-methyl-4-[(6- methyl-3-pyridinyl)carbonyl]- 1-piperazinyl}sulfonyl)benzo- nitrile

385 73 1-({4- [(difluoromethyl)oxy]phenyl} sulfonyl)-4-[(6-methyl-3-pyridinyl)carbonyl]piperazine

412

Example 741-[(6-methyl-3-pyridinyl)carbonyl]-4-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}piperazine

The compound of Example 74 was prepared in a similar manner as thecompound of Example 49 using the corresponding reactants.

m/z (API-ES) 428 [M+H]⁺

Example 75(2S)-1-{[6-(1-Azetidinyl)-4-methyl-3-pyridinyl]carbonyl}-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

(2S)-1-[(6-Fluoro-4-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine(may be prepared as described in Example 27) (67 mg, 0.15 mmol) wasweighed into a microwave vial and dissolved in isopropanol (1.5 ml).Azetidine (0.203 ml, 3.01 mmol) was added and the mixture was heated inthe microwave to 120° C. for 12 h with stirring. The reaction mixturewas concentrated to give the crude material as a colourless gum (˜187mg). This was purified by MDAP to give the title compound as a paleyellow gum (67 mg). The gum was redissolved in MeOH, water was added,and the mixture was concentrated under a flow of argon then dried invacuo to give the title compound as a colourless solid.

m/z (API-ES) 483 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) 8 ppm 1.32-1.45 (m, 3 H), 2.16 (s, 3 H),2.24-2.35 (m, 1 H), 2.36-2.53 (m, 3 H), 3.26-3.41 (m, 1 H), 3.55-3.67(m, 1 H), 3.70-3.83 (m, 1 H), 4.04 (t, J=7.5 Hz, 4 H), 4.0-4.5 (v br, 1H), 4.6-5.1 (v br, 1 H), 6.05 (s, 1 H), 7.77-7.90 (m, 5 H).

Example 764-({(3S)-4-[(6-cyclopropyl-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile

Argon was bubbled through a solution of4-({(3S)-4-[(6-iodo-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(50.0 mg, 0.098 mmol) (may be prepared as described in Example 50),potassium phosphate (72.8 mg, 0.343 mmol) and cyclopropylboronic acid(25.2 mg, 0.294 mmol) in toluene (3 mL) and water (200 μl) for 30 min.Tricyclohexylphosphine (2.75 mg, 9.80 μmol) and palladium(II)acetate(1.100 mg, 4.90 μmol) were added and the resulting pale yellow solutionheated at 100° C. for 2 h. LCMS had not changed from 1 min, at 45° C.The solution was cooled and concentrated under vacuum to leave a paleyellow solid. Purification by MDAP and concentration of the desiredfractions gave the title compound (1.0 mg) as a clear film, and a batchof recovered4-({(3S)-4-[(6-iodo-3-pyridinyl)carbonyl]-3-methyl-1-piperazinyl}sulfonyl)-3-methylbenzonitrile(28.2 mg) starting material.

m/z (API-ES) 425 [M+H]⁺

¹H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.03-1.07 (m, 4H), 1.36 (d, J=7.2Hz, 3H), 2.06 (m, 1H), 2.68 (s, 3H), 2.71 (td, J=12.0, 3.2 Hz, 1H), 2.89(dd, J=12.0, 3.2 Hz, 1H), 3.35 (m, 1H), 3.58 (m, 1H), 3.73 (m, 1H), 4.12(brm, 1H), 4.53 (brm, 1H), 7.19 (d, J=8.4 Hz, 1H), 7.56 (dd, J=8.4, 2.4Hz, 1H), 7.60-7.67 (m, 2H), 7.95 (d, J=8.4 Hz, 1H), 8.42 (d, J=2.4 Hz,1H)

Equipment:

Mass-Directed Automated HPLC/Mass-Directed Automated Preparation (MDAP)

Where indicated in the above compounds, purification by mass-directedautomated HPLC was carried out using the following apparatus andconditions:

Hardware

-   Waters 2525 Binary Gradient Module-   Waters 515 Makeup Pump-   Waters Pump Control Module-   Waters 2767 Inject Collect-   Waters Column Fluidics Manager-   Waters 2996 Photodiode Array Detector-   Waters ZQ Mass Spectrometer-   Gilson 202 fraction collector-   Gilson Aspec waste collector    Software-   Waters MassLynx version 4 SP2    Column

The columns used are Waters Atlantis, the dimensions of which are 19mm×100 mm (small scale) and 30 mm×100 mm (large scale). The stationaryphase particle size is 5 μm.

Solvents

-   A: Aqueous solvent=Water+0.1% Formic Acid-   B: Organic solvent=Acetonitrile+0.1% Formic Acid-   Make up solvent=Methanol:Water 80:20-   Needle rinse solvent=Methanol

Methods

There are five methods used depending on the analytical retention timeof the compound of interest. They have a 13.5-minute runtime, whichcomprises of a 10-minute gradient followed by a 3.5 minute column flushand re-equilibration step.

-   Large/Small Scale 1.0-1.5=5-30% B-   Large/Small Scale 1.5-2.2=15-55% B-   Large/Small Scale 2.2-2.9=30-85% B-   Large/Small Scale 2.9-3.6=50-99% B-   Large/Small Scale 3.6-5.0=80-99% B (in 6 minutes followed by 7.5    minutes flush and re-equilibration)    Flow Rate

All of the above methods have a flow rate of either 20 mls/min (SmallScale) or 40 mls/min (Large Scale).

Liquid Chromatography/Mass Spectrometry

Analysis of the above compounds by Liquid Chromatography/MassSpectrometry (LC/MS) was carried out using the following apparatus andconditions:

Hardware

-   Waters Acquity Binary Solvent Manager-   Waters Acquity Sample Manager-   Waters Acquity PDA-   Waters ZQ Mass Spectrometer-   Sedere Sedex 75    Software-   Waters MassLynx version 4.1    Column

The column used is a Waters Acquity BEH UPLC C18, the dimensions ofwhich are 2.1 mm×50 mm. The stationary phase particle size is 1.7 μm.

Solvents

-   A: Aqueous solvent=Water+0.05% Formic Acid-   B: Organic solvent=Acetonitrile+0.05% Formic Acid-   Weak Wash=1:1 Methanol:Water-   Strong Wash=Water    Method

The generic method used has a 2 minute runtime.

Time/min % B 0 3 0.1 3 1.5 97 1.9 97 2.0 3

The above method has a flow rate of 1 ml/min.

-   The injection volume for the generic method is 0.5 ul-   The column temperature is 40° C.-   The UV detection range is from 220 to 330 nm    Biotage SP4®

Biotage-SP4® is an automated purification system. It uses preloadedsilica gel columns.

The user applies their material to the top of the column and choosessolvents, gradients, flow rates, column size, collection method andeluting volumes.

Phase Separators (Hydrophobic Frit)

Phase separators are a range of ISOLUTE® columns fitted with anoptimized frit material that easily separates aqueous phase fromchlorinated solvents under gravity.

SCX—Strong Cation Exchange Cartridge

Where indicated in the compounds, an SCX cartridge was used as part ofthe compound purification process. Typically an ISOLUTE SCX-2 cartridgewas used. ISOLUTE SCX-2 is a silica-based sorbent with a chemicallybonded propylsulfonic acid functional group.

-   ISOLUTE SCX-2 Chemical Data-   Base Material: Silica, 50 μm-   Functional Group Propylsulfonic acid-   Capacity: 0.6 meq/g-   Counter Ion: Proton    Pharmacological Data

Compounds of the invention may be tested for in vitro biologicalactivity in the hCa_(V)2.2 assay in accordance with the followingstudies:

Methods

Cell Biology

Stable cell lines expressing the human Ca_(V)2.2 α (als) subunit, alongwith the human 33 and α2δ1 auxiliary subunits were created followingsequential transfection and selection of human embryonic kidney (HEK293)cells. HEK293 cells were cultured in Dulbecco's modified Eaglesmedia/F12 media (Invitrogen, Cat #041-95750V) containing 10% foetalbovine serum, with added L-glutamine (2 mM; Invitrogen, Cat #25030-024)and non-essential amino acids (5%; Invitrogen, Cat #11140-035).Initially HEK293 cells were transfected with two plasmid vectors forexpression of the hCa_(V)2.2 α subunit (pCIN5-hCa_(V)2.2 which carries aneomycin resistance marker) and the hCa_(V) β3 subunit (pCIH-hCa_(V) β3which carries a hygromycin resistance marker). Clonal cell lines wereisolated following selection in media supplemented with 0.4 mg ml⁻¹Geneticin G418 (Invitrogen, Cat #10131-027) and 0.1 mg ml¹ hygromycin(Invitrogen, Cat #10687-010). These clonal cell lines were assessed forCa_(v)2.2α/β3-mediated current expression using the IonWorks planararray electrophysiology technology (described below). A clonal line wasidentified that gave a reasonable level of functional Ca_(v)2.2α/β3current expression. This cell line was transfected with a plasmid vectorfor expression of the human a251 subunit (pCIP-α2δ1 which carries apuromycin resistance marker) and clonal cell lines isolated followingselection in media containing 0.62 μg ml⁻¹ puromycin (Sigma, Cat#P-7255), in addition to 0.4 mg ml⁻¹ Geneticin G418 and 0.1 mg ml⁻¹hygromycin. Several cell lines were identified that gave robust levelsof Ca_(v)2.2α/β3/α2δ1-mediated current expression and one of these wasselected for compound profiling. Expression of all three subunits withinthis cell line was continuously maintained by the inclusion of G418 (0.4mg ml⁻¹), hygromycin (0.1 mg ml⁻¹) and puromycin (0.62 μg ml⁻¹). Cellswere maintained at 37° C. in a humidified environment containing 5% CO₂in air. Cells were liberated from the T175 culture flasks for passageand harvesting using TrpLE (Invitrogen, Cat #12604-013).

Cell Preparation

Cells were grown to 30-60% confluence in T175 flasks and maintained at30° C. for 24 hrs prior to recording. Cells were lifted by removing thegrowth media, washing with Ca²⁺ free PBS (Invitrogen, Cat #14190-094)and incubating with 3 ml of warmed (37° C.) TrpLE (Invitrogen, Cat#12604-013) for 6 minutes. Lifted cells were suspended in 10 ml ofextracellular buffer. Cell suspension was then placed into a 15 ml tubeand centrifuged for 2 minutes at 700 rpm. After centrifugation, thesupernatant was removed and the cell pellet was resuspended in 4.5 ml ofextracellular solution.

Electrophysiology

Currents were recorded at room temperature (21-23° C.) using theIonWorks planar array electrophysiology technology (Molecular DevicesCorp.). Stimulation protocols and data acquisition were carried outusing a microcomputer (Dell Pentium 4). In order to determine planarelectrode hole resistances (Rp), a 10 mV, 160 ms potential differencewas applied across each hole. These measurements were performed beforecell addition. After cell addition a seal test was performed prior toantibiotic (amphotericin) circulation to achieve intracellular access.Leak subtraction was conducted in all experiments by applying a 160 mshyperpolarizing (10 mV) prepulse 200 ms before the test pulses tomeasure leak conductance. Test pulses stepping from the holdingpotential (V_(H)) of −90 mV to +10 mV were applied for 20 ms andrepeated 10 times at a frequency of 10 Hz. In all experiments, the testpulse protocol was performed in the absence (pre-read) and presence(post-read) of a compound. Pre- and post-reads were separated by acompound addition followed by a 3-3.5 min incubation.

Solutions and Drugs

The intracellular solution contained the following (in mM): K-gluconate120, KCl 20 mM, MgCl₂ 5, EGTA 5, HEPES 10, adjusted to pH 7.3.Amphotericin was prepared as 30 mg/ml stock solution and diluted to afinal working concentration of 0.2 mg ml⁻¹ in intracellular buffersolution. The extracellular solution contained the following (in mM):Na-gluconate 120, NaCl 20, MgCl₂ 1, HEPES 10, BaCl₂ 5, adjusted to pH7.4.

Compounds were prepared in DMSO as 10 mM stock solutions and subsequent1:3 serial dilutions performed. Finally the compounds were diluted 1:100in external solution resulting in a final DMSO concentration of 1%.

Data Analysis

The recordings were analysed and filtered using seal resistance (>40MΩ), resistance reduction (>35%) and peak current amplitude (>200 pA) inthe absence of compound to eliminate unsuitable cells from furtheranalysis. Paired comparisons between pre-compound and post-compoundadditions were used to determine the inhibitory effect of each compound.The concentrations of compounds required to inhibit current elicited bythe 1^(st) depolarising pulse by 50% (tonic pIC50) were determined byfitting of the Hill equation to the concentration response data. Inaddition the use-dependent inhibitory properties of the compounds weredetermined by assessing the effect of compounds on the 10^(th) versus1^(st) depolarising pulse. The ratio of the 10^(th) over 1^(st) pulsewas determined in the absence and presence of drug and the %use-dependent inhibition calculated. The data was fitted using the sameequation as for the tonic pIC₅₀ and the concentration producing 30%inhibition (use-dependent pUD₃₀) determined.

The compounds of Examples 1 to 49 and 52 to 74 were tested in thehCa_(V)2.2 assay and demonstrated the following pUD₃₀ and pIC₅₀ values.Compounds were tested in the form as described in the Examples. Allcompounds tested have been tested one or more times (up to 11 times).Variations in pUD₃₀ and pIC₅₀ values may arise between tests.

The compounds 1 to 49 and 52 to 74 exhibited a pUD₃₀ value of 4.5 ormore than 4.5. The compounds 1 to 4, 6, 7, 9, 11 to 19, 21 to 25, 28 to49, 53 to 57, 59, 61, 63, 65 to 69, 71 and 74 exhibited a pUD₃₀ value of5.0 or more than 5.0. The compounds 1, 6, 7, 14, 21, 24, 25, 28, 30 to34, 36, 37, 39 to 41, 43 to 49, 54 to 57, 61, 69, 71 and 74 exhibited apUD₃₀ value of 5.5 or more than 5.5.

The compounds 1 to 25, 28 to 30, 34, 35, 38 to 42, 44, 45, 47, 52 to 53,56 to 74 exhibited a mean pIC₅₀ value of 5.0 or less than 5.0. Thecompounds 1 to 23, 38 to 40, 52, 53, 57 to 59, 61 to 74 exhibited a meanpIC₅₀ value of 4.5 or less than 4.5.

The invention claimed is:
 1. A compound of formula (I)

wherein m is 1; wherein n is 0, 1 or 2; where present, each R¹ isindependently selected from C₁₋₄ alkyl, C₁₋₄ alkoxy, C₃₋₆ cycloalkyl,cyano, NR^(1a)R^(1b) and halogen; R^(1a) and R^(1b) are independentlyselected from hydrogen, C₁₋₄ alkyl, C₃₋₆ cycloalkyl and a 4 to 6membered heterocyclyl; or R^(1a) and R^(1b) together with the nitrogenatom to which they are attached form a 4 to 6 membered heterocyclicring; R² is methyl; R³ is hydrogen, halogen, cyano, C₁₋₄ haloalkyl orC₁₋₄ haloalkoxy; R⁴ is hydrogen or C₁₋₄ alkyl; R⁵ is hydrogen, halogen,cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy; and R⁶ is hydrogen, halogen,cyano, C₁₋₄ haloalkyl or C₁₋₄ haloalkoxy, wherein at least 1 of R³, R⁴,R⁵ and R⁶ is a group other than hydrogen.